diff --git a/powershell/ql/lib/semmle/code/powershell/ast/internal/CallExpr.qll b/powershell/ql/lib/semmle/code/powershell/ast/internal/CallExpr.qll
index 96659f6cda24..c8dd8dbc9ad5 100644
--- a/powershell/ql/lib/semmle/code/powershell/ast/internal/CallExpr.qll
+++ b/powershell/ql/lib/semmle/code/powershell/ast/internal/CallExpr.qll
@@ -28,6 +28,10 @@ class CallExpr extends Expr, TCallExpr {
   /** Gets the qualifier of this call, if any. */
   Expr getQualifier() { none() }
 
+  Expr getPipelineArgument() {
+    exists(Pipeline p, int i | this = p.getComponent(i + 1) and result = p.getComponent(i))
+  }
+
   final override string toString() { result = "Call to " + this.getName() }
 
   predicate isStatic() { none() }
@@ -52,3 +56,11 @@ class Qualifier extends Expr {
 
   CallExpr getCall() { result = call }
 }
+
+class PipelineArgument extends Expr {
+  CallExpr call;
+
+  PipelineArgument() { this = call.getPipelineArgument() }
+
+  CallExpr getCall() { result = call }
+}
diff --git a/powershell/ql/lib/semmle/code/powershell/ast/internal/ChildIndex.qll b/powershell/ql/lib/semmle/code/powershell/ast/internal/ChildIndex.qll
index 01eefb967621..df29eb7f516d 100644
--- a/powershell/ql/lib/semmle/code/powershell/ast/internal/ChildIndex.qll
+++ b/powershell/ql/lib/semmle/code/powershell/ast/internal/ChildIndex.qll
@@ -36,14 +36,87 @@ newtype ChildIndex =
   // PipelineByPropertNameVar(Raw::PipelineByPropertyNameParameter p) or
   PipelineIteratorVar() or
   PipelineByPropertyNameIteratorVar(Raw::PipelineByPropertyNameParameter p) or
-  RealVar(string name) { name = variableNameInScope(_, _) }
+  RealVar(string name) { name = variableNameInScope(_, _) } or
+  ProcessBlockPipelineVarReadAccess()
 
 int synthPipelineParameterChildIndex(Raw::ScriptBlock sb) {
+  // If there is a parameter block, but no pipeline parameter
   exists(Raw::ParamBlock pb |
     pb = sb.getParamBlock() and
     not pb.getAParameter() instanceof Raw::PipelineParameter and
     result = pb.getNumParameters()
   )
+  or
+  // There is no parameter block
+  not exists(sb.getParamBlock()) and
+  exists(Raw::FunctionDefinitionStmt funDefStmt |
+    funDefStmt.getBody() = sb and
+    result = funDefStmt.getNumParameters()
+  )
+}
+
+string stringOfChildIndex(ChildIndex i) {
+  exists(Raw::ChildIndex rawIndex |
+    i = RawChildIndex(rawIndex) and
+    result = Raw::stringOfChildIndex(rawIndex)
+  )
+  or
+  i = ParamPipeline() and
+  result = "ParamPipeline"
+  or
+  i = ParamDefaultVal() and
+  result = "ParamDefaultVal"
+  or
+  i = FunParam(_) and
+  result = "FunParam"
+  or
+  i = CmdArgument(_) and
+  result = "CmdArgument"
+  or
+  i = ExprStmtExpr() and
+  result = "ExprStmtExpr"
+  or
+  i = MethodBody() and
+  result = "MethodBody"
+  or
+  i = ThisVar() and
+  result = "ThisVar"
+  or
+  i = PipelineParamVar() and
+  result = "PipelineParamVar"
+  or
+  i = PipelineIteratorVar() and
+  result = "PipelineIteratorVar"
+  or
+  i = PipelineByPropertyNameIteratorVar(_) and
+  result = "PipelineByPropertyNameIteratorVar"
+  or
+  i = RealVar(_) and
+  result = "RealVar"
+  or
+  i = ExprRedirection(_) and
+  result = "ExprRedirection"
+  or
+  i = FunDefFun() and
+  result = "FunDefFun"
+  or
+  i = TypeDefType() and
+  result = "TypeDefType"
+  or
+  i = TypeMember(_) and
+  result = "TypeMember"
+  or
+  i = ScriptBlockAttr(_) and
+  result = "ScriptBlockAttr"
+  or
+  i = ParamAttr(_) and
+  result = "ParamAttr"
+  or
+  i = FunctionBody() and
+  result = "FunctionBody"
+  or
+  i = ProcessBlockPipelineVarReadAccess() and
+  result = "ProcessBlockPipelineVarReadAccess"
 }
 
 Raw::ChildIndex toRawChildIndex(ChildIndex i) { i = RawChildIndex(result) }
@@ -265,3 +338,5 @@ ChildIndex usingExprExpr() { result = RawChildIndex(Raw::UsingExprExpr()) }
 ChildIndex whileStmtCond() { result = RawChildIndex(Raw::WhileStmtCond()) }
 
 ChildIndex whileStmtBody() { result = RawChildIndex(Raw::WhileStmtBody()) }
+
+ChildIndex processBlockPipelineVarReadAccess() { result = ProcessBlockPipelineVarReadAccess() }
diff --git a/powershell/ql/lib/semmle/code/powershell/ast/internal/NamedBlock.qll b/powershell/ql/lib/semmle/code/powershell/ast/internal/NamedBlock.qll
index a23106fff648..10da368db65e 100644
--- a/powershell/ql/lib/semmle/code/powershell/ast/internal/NamedBlock.qll
+++ b/powershell/ql/lib/semmle/code/powershell/ast/internal/NamedBlock.qll
@@ -50,6 +50,14 @@ class ProcessBlock extends NamedBlock {
     result = this.getEnclosingFunction().getPipelineParameter()
   }
 
+  PipelineIteratorVariable getPipelineIteratorVariable() {
+    result = TVariableSynth(getRawAst(this), PipelineIteratorVar())
+  }
+
+  VarReadAccess getPipelineParameterAccess() {
+    synthChild(getRawAst(this), processBlockPipelineVarReadAccess(), result)
+  }
+
   PipelineByPropertyNameParameter getAPipelineByPropertyNameParameter() {
     result = scriptBlock.getEnclosingFunction().getAParameter()
   }
diff --git a/powershell/ql/lib/semmle/code/powershell/ast/internal/Raw/ChildIndex.qll b/powershell/ql/lib/semmle/code/powershell/ast/internal/Raw/ChildIndex.qll
index 8da1c5e2fb22..b78fb4e16442 100644
--- a/powershell/ql/lib/semmle/code/powershell/ast/internal/Raw/ChildIndex.qll
+++ b/powershell/ql/lib/semmle/code/powershell/ast/internal/Raw/ChildIndex.qll
@@ -99,3 +99,201 @@ newtype ChildIndex =
   UsingExprExpr() or
   WhileStmtCond() or
   WhileStmtBody()
+
+string stringOfChildIndex(ChildIndex i) {
+  i = ArrayExprStmtBlock() and result = "ArrayExprStmtBlock"
+  or
+  i = ArrayLiteralExpr(_) and result = "ArrayLiteralExpr"
+  or
+  i = AssignStmtLeftHandSide() and result = "AssignStmtLeftHandSide"
+  or
+  i = AssignStmtRightHandSide() and result = "AssignStmtRightHandSide"
+  or
+  i = AttributeNamedArg(_) and result = "AttributeNamedArg"
+  or
+  i = AttributePosArg(_) and result = "AttributePosArg"
+  or
+  i = AttributedExprExpr() and result = "AttributedExprExpr"
+  or
+  i = AttributedExprAttr() and result = "AttributedExprAttr"
+  or
+  i = BinaryExprLeft() and result = "BinaryExprLeft"
+  or
+  i = BinaryExprRight() and result = "BinaryExprRight"
+  or
+  i = CatchClauseBody() and result = "CatchClauseBody"
+  or
+  i = CatchClauseType(_) and result = "CatchClauseType"
+  or
+  i = CmdElement_(_) and result = "CmdElement"
+  or
+  i = CmdCallee() and result = "CmdCallee"
+  or
+  i = CmdRedirection(_) and result = "CmdRedirection"
+  or
+  i = CmdExprExpr() and result = "CmdExprExpr"
+  or
+  i = ConfigurationName() and result = "ConfigurationName"
+  or
+  i = ConfigurationBody() and result = "ConfigurationBody"
+  or
+  i = ConvertExprExpr() and result = "ConvertExprExpr"
+  or
+  i = ConvertExprType() and result = "ConvertExprType"
+  or
+  i = ConvertExprAttr() and result = "ConvertExprAttr"
+  or
+  i = DataStmtBody() and result = "DataStmtBody"
+  or
+  i = DataStmtCmdAllowed(_) and result = "DataStmtCmdAllowed"
+  or
+  i = DoUntilStmtCond() and result = "DoUntilStmtCond"
+  or
+  i = DoUntilStmtBody() and result = "DoUntilStmtBody"
+  or
+  i = DoWhileStmtCond() and result = "DoWhileStmtCond"
+  or
+  i = DoWhileStmtBody() and result = "DoWhileStmtBody"
+  or
+  i = DynamicStmtName() and result = "DynamicStmtName"
+  or
+  i = DynamicStmtBody() and result = "DynamicStmtBody"
+  or
+  i = ExitStmtPipeline() and result = "ExitStmtPipeline"
+  or
+  i = ExpandableStringExprExpr(_) and result = "ExpandableStringExprExpr"
+  or
+  i = ForEachStmtVar() and result = "ForEachStmtVar"
+  or
+  i = ForEachStmtIter() and result = "ForEachStmtIter"
+  or
+  i = ForEachStmtBody() and result = "ForEachStmtBody"
+  or
+  i = ForStmtInit() and result = "ForStmtInit"
+  or
+  i = ForStmtCond() and result = "ForStmtCond"
+  or
+  i = ForStmtIter() and result = "ForStmtIter"
+  or
+  i = ForStmtBody() and result = "ForStmtBody"
+  or
+  i = FunDefStmtBody() and result = "FunDefStmtBody"
+  or
+  i = FunDefStmtParam(_) and result = "FunDefStmtParam"
+  or
+  i = GotoStmtLabel() and result = "GotoStmtLabel"
+  or
+  i = HashTableExprKey(_) and result = "HashTableExprKey"
+  or
+  i = HashTableExprStmt(_) and result = "HashTableExprStmt"
+  or
+  i = IfStmtElse() and result = "IfStmtElse"
+  or
+  i = IfStmtCond(_) and result = "IfStmtCond"
+  or
+  i = IfStmtThen(_) and result = "IfStmtThen"
+  or
+  i = IndexExprIndex() and result = "IndexExprIndex"
+  or
+  i = IndexExprBase() and result = "IndexExprBase"
+  or
+  i = InvokeMemberExprQual() and result = "InvokeMemberExprQual"
+  or
+  i = InvokeMemberExprCallee() and result = "InvokeMemberExprCallee"
+  or
+  i = InvokeMemberExprArg(_) and result = "InvokeMemberExprArg"
+  or
+  i = MemberExprQual() and result = "MemberExprQual"
+  or
+  i = MemberExprMember() and result = "MemberExprMember"
+  or
+  i = NamedAttributeArgVal() and result = "NamedAttributeArgVal"
+  or
+  i = MemberAttr(_) and result = "MemberAttr"
+  or
+  i = MemberTypeConstraint() and result = "MemberTypeConstraint"
+  or
+  i = NamedBlockStmt(_) and result = "NamedBlockStmt"
+  or
+  i = NamedBlockTrap(_) and result = "NamedBlockTrap"
+  or
+  i = ParamBlockAttr(_) and result = "ParamBlockAttr"
+  or
+  i = ParamBlockParam(_) and result = "ParamBlockParam"
+  or
+  i = ParamAttr(_) and result = "ParamAttr"
+  or
+  i = ParamDefaultVal() and result = "ParamDefaultVal"
+  or
+  i = ParenExprExpr() and result = "ParenExprExpr"
+  or
+  i = PipelineComp(_) and result = "PipelineComp"
+  or
+  i = PipelineChainLeft() and result = "PipelineChainLeft"
+  or
+  i = PipelineChainRight() and result = "PipelineChainRight"
+  or
+  i = ReturnStmtPipeline() and result = "ReturnStmtPipeline"
+  or
+  i = RedirectionExpr() and result = "RedirectionExpr"
+  or
+  i = ScriptBlockUsing(_) and result = "ScriptBlockUsing"
+  or
+  i = ScriptBlockParamBlock() and result = "ScriptBlockParamBlock"
+  or
+  i = ScriptBlockBeginBlock() and result = "ScriptBlockBeginBlock"
+  or
+  i = ScriptBlockCleanBlock() and result = "ScriptBlockCleanBlock"
+  or
+  i = ScriptBlockDynParamBlock() and result = "ScriptBlockDynParamBlock"
+  or
+  i = ScriptBlockEndBlock() and result = "ScriptBlockEndBlock"
+  or
+  i = ScriptBlockProcessBlock() and result = "ScriptBlockProcessBlock"
+  or
+  i = ScriptBlockExprBody() and result = "ScriptBlockExprBody"
+  or
+  i = StmtBlockStmt(_) and result = "StmtBlockStmt"
+  or
+  i = StmtBlockTrapStmt(_) and result = "StmtBlockTrapStmt"
+  or
+  i = ExpandableSubExprExpr() and result = "ExpandableSubExprExpr"
+  or
+  i = SwitchStmtCond() and result = "SwitchStmtCond"
+  or
+  i = SwitchStmtDefault() and result = "SwitchStmtDefault"
+  or
+  i = SwitchStmtCase(_) and result = "SwitchStmtCase"
+  or
+  i = SwitchStmtPat(_) and result = "SwitchStmtPat"
+  or
+  i = CondExprCond() and result = "CondExprCond"
+  or
+  i = CondExprTrue() and result = "CondExprTrue"
+  or
+  i = CondExprFalse() and result = "CondExprFalse"
+  or
+  i = ThrowStmtPipeline() and result = "ThrowStmtPipeline"
+  or
+  i = TryStmtBody() and result = "TryStmtBody"
+  or
+  i = TryStmtCatchClause(_) and result = "TryStmtCatchClause"
+  or
+  i = TryStmtFinally() and result = "TryStmtFinally"
+  or
+  i = TypeStmtMember(_) and result = "TypeStmtMember"
+  or
+  i = TypeStmtBaseType(_) and result = "TypeStmtBaseType"
+  or
+  i = TrapStmtBody() and result = "TrapStmtBody"
+  or
+  i = TrapStmtTypeConstraint() and result = "TrapStmtTypeConstraint"
+  or
+  i = UnaryExprOp() and result = "UnaryExprOp"
+  or
+  i = UsingExprExpr() and result = "UsingExprExpr"
+  or
+  i = WhileStmtCond() and result = "WhileStmtCond"
+  or
+  i = WhileStmtBody() and result = "WhileStmtBody"
+}
diff --git a/powershell/ql/lib/semmle/code/powershell/ast/internal/Raw/Function.qll b/powershell/ql/lib/semmle/code/powershell/ast/internal/Raw/Function.qll
index 6b303fb36be5..d1e9a572a02b 100644
--- a/powershell/ql/lib/semmle/code/powershell/ast/internal/Raw/Function.qll
+++ b/powershell/ql/lib/semmle/code/powershell/ast/internal/Raw/Function.qll
@@ -11,6 +11,8 @@ class FunctionDefinitionStmt extends @function_definition, Stmt {
 
   Parameter getAParameter() { result = this.getParameter(_) }
 
+  int getNumParameters() { result = count(this.getParameter(_)) }
+
   override Ast getChild(ChildIndex i) {
     i = FunDefStmtBody() and result = this.getBody()
     or
diff --git a/powershell/ql/lib/semmle/code/powershell/ast/internal/Raw/Parameter.qll b/powershell/ql/lib/semmle/code/powershell/ast/internal/Raw/Parameter.qll
index 32669d0141ea..08ee3f9e2091 100644
--- a/powershell/ql/lib/semmle/code/powershell/ast/internal/Raw/Parameter.qll
+++ b/powershell/ql/lib/semmle/code/powershell/ast/internal/Raw/Parameter.qll
@@ -35,7 +35,7 @@ class PipelineParameter extends Parameter {
       this.getAnAttribute().(Attribute).getANamedArgument() = namedAttribute and
       namedAttribute.getName().toLowerCase() = "valuefrompipeline"
     |
-      namedAttribute.getValue().(ConstExpr).getValue().getValue() = "true"
+      namedAttribute.getValue().(ConstExpr).getValue().getValue().toLowerCase() = "true"
       or
       not exists(namedAttribute.getValue().(ConstExpr).getValue().getValue())
     )
@@ -50,7 +50,7 @@ class PipelineByPropertyNameParameter extends Parameter {
       this.getAnAttribute().(Attribute).getANamedArgument() = namedAttribute and
       namedAttribute.getName().toLowerCase() = "valuefrompipelinebypropertyname"
     |
-      namedAttribute.getValue().(ConstExpr).getValue().getValue() = "true"
+      namedAttribute.getValue().(ConstExpr).getValue().getValue().toLowerCase() = "true"
       or
       not exists(namedAttribute.getValue().(ConstExpr).getValue().getValue())
     )
diff --git a/powershell/ql/lib/semmle/code/powershell/ast/internal/Raw/VariableExpression.qll b/powershell/ql/lib/semmle/code/powershell/ast/internal/Raw/VariableExpression.qll
index 00bc726699c5..c3088de4444d 100644
--- a/powershell/ql/lib/semmle/code/powershell/ast/internal/Raw/VariableExpression.qll
+++ b/powershell/ql/lib/semmle/code/powershell/ast/internal/Raw/VariableExpression.qll
@@ -24,6 +24,10 @@ class VarAccess extends @variable_expression, Expr {
   boolean isVariable() { variable_expression(this, _, _, _, _, _, _, _, _, _, result, _) }
 
   boolean isDriveQualified() { variable_expression(this, _, _, _, _, _, _, _, _, _, _, result) }
+
+  predicate isReadAccess() { not this.isWriteAccess() }
+
+  predicate isWriteAccess() { any(AssignStmt assign).getLeftHandSide() = this }
 }
 
 class ThisAccess extends VarAccess {
diff --git a/powershell/ql/lib/semmle/code/powershell/ast/internal/Synthesis.qll b/powershell/ql/lib/semmle/code/powershell/ast/internal/Synthesis.qll
index d58b2eb11b04..30356666b25f 100644
--- a/powershell/ql/lib/semmle/code/powershell/ast/internal/Synthesis.qll
+++ b/powershell/ql/lib/semmle/code/powershell/ast/internal/Synthesis.qll
@@ -587,6 +587,57 @@ private module CmdArguments {
  * Synthesize literals from known constant strings.
  */
 private module LiteralSynth {
+  pragma[nomagic]
+  private predicate assignmentHasLocation(
+    Raw::Scope scope, string name, File file, int startLine, int startColumn
+  ) {
+    Raw::isAutomaticVariableAccess(_, name) and
+    exists(Raw::Ast n, Location loc |
+      scopeAssigns(scope, name, n) and
+      loc = n.getLocation() and
+      file = loc.getFile() and
+      startLine = loc.getStartLine() and
+      startColumn = loc.getStartColumn()
+    )
+  }
+
+  pragma[nomagic]
+  private predicate varAccessHasLocation(
+    Raw::VarAccess va, File file, int startLine, int startColumn
+  ) {
+    exists(Location loc |
+      loc = va.getLocation() and
+      loc.getFile() = file and
+      loc.getStartLine() = startLine and
+      loc.getStartColumn() = startColumn
+    )
+  }
+
+  /**
+   * Holds if `va` is an access to the automatic variable named `name`.
+   * 
+   * Unlike `Raw::isAutomaticVariableAccess`, this predicate also checks for
+   * shadowing.
+   */
+  private predicate isAutomaticVariableAccess(Raw::VarAccess va, string name) {
+    Raw::isAutomaticVariableAccess(va, name) and
+    exists(Raw::Scope scope, File file, int startLine, int startColumn |
+      scope = Raw::scopeOf(va) and
+      varAccessHasLocation(va, file, startLine, startColumn)
+    |
+      // If it's a read then make sure there is no assignment precedeeding it
+      va.isReadAccess() and
+      not exists(int assignStartLine, int assignStartCoumn |
+        assignmentHasLocation(scope, name, file, assignStartLine, assignStartCoumn)
+      |
+        assignStartLine < startLine
+        or
+        assignStartLine = startLine and
+        assignStartCoumn < startColumn
+      )
+    )
+  }
+
   private class LiteralSynth extends Synthesis {
     final override predicate isRelevant(Raw::Ast a) {
       exists(Raw::VarAccess va | a = va |
@@ -598,7 +649,7 @@ private module LiteralSynth {
         or
         Raw::isEnvVariableAccess(va, _)
         or
-        Raw::isAutomaticVariableAccess(va, _)
+        isAutomaticVariableAccess(va, _)
       )
     }
 
@@ -628,7 +679,7 @@ private module LiteralSynth {
         Raw::isEnvVariableAccess(va, s) and
         child = SynthChild(EnvVariableKind(s))
         or
-        Raw::isAutomaticVariableAccess(va, s) and
+        isAutomaticVariableAccess(va, s) and
         child = SynthChild(AutomaticVariableKind(s))
       )
     }
@@ -710,12 +761,25 @@ private module IteratorAccessSynth {
   }
 
   private class IteratorAccessSynth extends Synthesis {
+    final override predicate isRelevant(Raw::Ast a) {
+      exists(Raw::ProcessBlock pb, Raw::VarAccess va |
+        va = a and
+        pb = va.getParent+()
+      |
+        va.getUserPath() = "_"
+        or
+        va.getUserPath().toLowerCase() =
+          pb.getScriptBlock().getParamBlock().getPipelineParameter().getName().toLowerCase()
+      )
+    }
+
     private predicate expr(Raw::Ast rawParent, ChildIndex i, Raw::VarAccess va, Child child) {
       rawParent.getChild(toRawChildIndex(i)) = va and
       child = SynthChild(VarAccessSynthKind(this.varAccess(va)))
     }
 
     private predicate stmt(Raw::Ast rawParent, ChildIndex i, Raw::CmdExpr cmdExpr, Child child) {
+      exists(this.varAccess(cmdExpr.getExpr())) and
       rawParent.getChild(toRawChildIndex(i)) = cmdExpr and
       not mustHaveExprChild(rawParent, cmdExpr) and
       child = SynthChild(ExprStmtKind())
@@ -793,3 +857,31 @@ private module IteratorAccessSynth {
     }
   }
 }
+
+private module PipelineAccess {
+  private class PipelineAccess extends Synthesis {
+    final override predicate child(Raw::Ast parent, ChildIndex i, Child child) {
+      exists(Raw::ProcessBlock pb | parent = pb |
+        i = processBlockPipelineVarReadAccess() and
+        exists(PipelineVariable pipelineVar |
+          pipelineVar = TVariableSynth(pb.getScriptBlock(), PipelineParamVar()) and
+          child = SynthChild(VarAccessSynthKind(pipelineVar))
+        )
+      )
+    }
+
+    final override Location getLocation(Ast n) {
+      exists(ProcessBlock pb |
+        pb.getPipelineParameterAccess() = n and
+        result = pb.getLocation()
+      )
+    }
+
+    final override predicate getAnAccess(VarAccessSynth va, Variable v) {
+      exists(ProcessBlock pb |
+        pb.getPipelineParameterAccess() = va and
+        v = pb.getPipelineParameter()
+      )
+    }
+  }
+}
diff --git a/powershell/ql/lib/semmle/code/powershell/ast/internal/TAst.qll b/powershell/ql/lib/semmle/code/powershell/ast/internal/TAst.qll
index ee7c58d4f656..f62e71e58b91 100644
--- a/powershell/ql/lib/semmle/code/powershell/ast/internal/TAst.qll
+++ b/powershell/ql/lib/semmle/code/powershell/ast/internal/TAst.qll
@@ -17,8 +17,7 @@ string variableNameInScope(Raw::Ast n, Scope::Range scope) {
     not scope.getAParameter().(Raw::PipelineByPropertyNameParameter).getName() = result and
     not result.toLowerCase() = ["_", "this", "false", "true", "null"] and
     not parameter(_, n, _, _) and
-    not Raw::isEnvVariableAccess(n, _) and
-    not Raw::isAutomaticVariableAccess(n, _)
+    not Raw::isEnvVariableAccess(n, _)
     or
     any(Synthesis s).explicitAssignment(n, result, _)
     or
@@ -26,7 +25,7 @@ string variableNameInScope(Raw::Ast n, Scope::Range scope) {
   )
 }
 
-private predicate scopeAssigns(Scope::Range scope, string name, Raw::Ast n) {
+predicate scopeAssigns(Scope::Range scope, string name, Raw::Ast n) {
   (explicitAssignment(n, _) or implicitAssignment(n)) and
   name = variableNameInScope(n, scope)
 }
diff --git a/powershell/ql/lib/semmle/code/powershell/controlflow/CfgNodes.qll b/powershell/ql/lib/semmle/code/powershell/controlflow/CfgNodes.qll
index ef07239ab51e..c8126a68ab97 100644
--- a/powershell/ql/lib/semmle/code/powershell/controlflow/CfgNodes.qll
+++ b/powershell/ql/lib/semmle/code/powershell/controlflow/CfgNodes.qll
@@ -272,7 +272,13 @@ class NamedBlockCfgNode extends AstCfgNode {
   StmtNodes::TrapStmtCfgNode getATrapStmt() { result = this.getTrapStmt(_) }
 }
 
-private class ProcessBlockChildMapping extends NamedBlockChildMapping, ProcessBlock { }
+private class ProcessBlockChildMapping extends NamedBlockChildMapping, ProcessBlock {
+  override predicate relevantChild(Ast child) {
+    super.relevantChild(child)
+    or
+    child = super.getPipelineParameterAccess()
+  }
+}
 
 class ProcessBlockCfgNode extends NamedBlockCfgNode {
   override string getAPrimaryQlClass() { result = "ProcessBlockCfgNode" }
@@ -282,6 +288,18 @@ class ProcessBlockCfgNode extends NamedBlockCfgNode {
   override ProcessBlock getBlock() { result = block }
 
   ScriptBlockCfgNode getScriptBlock() { result.getProcessBlock() = this }
+
+  PipelineVariable getPipelineVariable() {
+    result.getScriptBlock() = this.getScriptBlock().getAstNode()
+  }
+
+  ExprNodes::VarReadAccessCfgNode getPipelineVariableAccess() {
+    block.hasCfgChild(block.getPipelineParameterAccess(), this, result)
+  }
+
+  PipelineIteratorVariable getPipelineIteratorVariable() {
+    result.getProcessBlock().getScriptBlock() = this.getScriptBlock().getAstNode()
+  }
 }
 
 private class CatchClauseChildMapping extends NonExprChildMapping, CatchClause {
@@ -520,6 +538,13 @@ module ExprNodes {
 
     ExprCfgNode getCallee() { e.hasCfgChild(e.getCallee(), this, result) }
 
+    ExprCfgNode getPipelineArgument() {
+      exists(ExprNodes::PipelineCfgNode pipeline, int i |
+        pipeline.getComponent(i + 1) = this and
+        result = pipeline.getComponent(i)
+      )
+    }
+
     predicate isStatic() { this.getExpr().isStatic() }
   }
 
@@ -984,6 +1009,12 @@ module ExprNodes {
     CallExprCfgNode getCall() { result.getQualifier() = this }
   }
 
+  class PipelineArgumentCfgNode extends ExprCfgNode {
+    override PipelineArgument e;
+
+    CallExprCfgNode getCall() { result.getPipelineArgument() = this }
+  }
+
   private class EnvVariableChildMapping extends ExprChildMapping, EnvVariable {
     override predicate relevantChild(Ast child) { none() }
   }
diff --git a/powershell/ql/lib/semmle/code/powershell/controlflow/internal/ControlFlowGraphImpl.qll b/powershell/ql/lib/semmle/code/powershell/controlflow/internal/ControlFlowGraphImpl.qll
index f67a748068e4..d28828481f56 100644
--- a/powershell/ql/lib/semmle/code/powershell/controlflow/internal/ControlFlowGraphImpl.qll
+++ b/powershell/ql/lib/semmle/code/powershell/controlflow/internal/ControlFlowGraphImpl.qll
@@ -193,21 +193,21 @@ module Trees {
       or
       exists(int i |
         last(super.getParameter(i), pred, c) and
-        completionIsNormal(c) and
+        completionIsNormal(c)
+      |
         first(super.getParameter(i + 1), succ)
-      )
-      or
-      last(super.getParameter(super.getNumberOfParameters() - 1), pred, c) and
-      completionIsNormal(c) and
-      (
-        first(super.getBeginBlock(), succ)
-        or
-        not exists(super.getBeginBlock()) and
-        first(super.getProcessBlock(), succ)
         or
-        not exists(super.getBeginBlock()) and
-        not exists(super.getProcessBlock()) and
-        first(super.getEndBlock(), succ)
+        not exists(super.getParameter(i + 1)) and
+        (
+          first(super.getBeginBlock(), succ)
+          or
+          not exists(super.getBeginBlock()) and
+          first(super.getProcessBlock(), succ)
+          or
+          not exists(super.getBeginBlock()) and
+          not exists(super.getProcessBlock()) and
+          first(super.getEndBlock(), succ)
+        )
       )
       or
       last(super.getBeginBlock(), pred, c) and
@@ -292,9 +292,55 @@ module Trees {
     final override predicate succEntry(Ast n, Completion c) { n = this and completionIsSimple(c) }
   }
 
-  class NamedBlockTree extends StandardPreOrderTree instanceof NamedBlock {
-    // TODO: Handle trap
-    override AstNode getChildNode(int i) { result = super.getStmt(i) }
+  abstract class NamedBlockTreeBase extends ControlFlowTree instanceof NamedBlock {
+    final override predicate last(Ast last, Completion c) {
+      exists(int i | last(super.getStmt(i), last, c) |
+        completionIsNormal(c) and
+        not exists(super.getStmt(i + 1))
+        or
+        not completionIsNormal(c)
+      )
+      or
+      not exists(super.getAStmt()) and
+      completionIsSimple(c) and
+      last = this
+    }
+
+    override predicate succ(Ast pred, Ast succ, Completion c) {
+      pred = this and
+      completionIsSimple(c) and
+      first(super.getStmt(0), succ)
+      or
+      exists(int i |
+        last(super.getStmt(i), pred, c) and
+        completionIsNormal(c) and
+        first(super.getStmt(i + 1), succ)
+      )
+    }
+
+    override predicate propagatesAbnormal(Ast child) { child = super.getAStmt() }
+  }
+
+  class NamedBlockTree extends NamedBlockTreeBase instanceof NamedBlock {
+    NamedBlockTree() { not this instanceof ProcessBlock }
+
+    final override predicate first(Ast first) { first = this }
+
+    final override predicate propagatesAbnormal(Ast child) { super.propagatesAbnormal(child) }
+  }
+
+  class ProcessBlockTree extends NamedBlockTreeBase instanceof ProcessBlock {
+    final override predicate first(Ast first) { first = super.getPipelineParameterAccess() }
+
+    final override predicate succ(Ast pred, Ast succ, Completion c) {
+      this.first(pred) and
+      completionIsSimple(c) and
+      succ = this
+      or
+      super.succ(pred, succ, c)
+    }
+
+    final override predicate propagatesAbnormal(Ast child) { super.propagatesAbnormal(child) }
   }
 
   class AssignStmtTree extends StandardPreOrderTree instanceof AssignStmt {
diff --git a/powershell/ql/lib/semmle/code/powershell/dataflow/internal/DataFlowPrivate.qll b/powershell/ql/lib/semmle/code/powershell/dataflow/internal/DataFlowPrivate.qll
index 46380b0a3e1b..d5bfa5c7a726 100644
--- a/powershell/ql/lib/semmle/code/powershell/dataflow/internal/DataFlowPrivate.qll
+++ b/powershell/ql/lib/semmle/code/powershell/dataflow/internal/DataFlowPrivate.qll
@@ -64,15 +64,24 @@ module SsaFlow {
     result = TNormalParameterNode(p.asParameter())
     or
     result = TThisParameterNode(p.asThis())
+    or
+    result = TPipelineParameterNode(p.asPipelineParameter())
   }
 
+  /** Gets the SSA node corresponding to the PowerShell node `n`. */
   Impl::Node asNode(Node n) {
     n = TSsaNode(result)
     or
     result.(Impl::ExprNode).getExpr() = n.asExpr()
     or
-    result.(Impl::ExprNode).getExpr() =
-      [n.(ProcessNode).getProcessBlock(), n.(ProcessPropertyByNameNode).getProcessBlock()]
+    exists(CfgNodes::ProcessBlockCfgNode pb, BasicBlock bb, int i |
+      n.(ProcessNode).getProcessBlock() = pb and
+      bb.getNode(i) = pb and
+      result
+          .(Impl::SsaDefinitionNode)
+          .getDefinition()
+          .definesAt(pb.getPipelineIteratorVariable(), bb, i)
+    )
     or
     result.(Impl::ExprPostUpdateNode).getExpr() = n.(PostUpdateNode).getPreUpdateNode().asExpr()
     or
@@ -115,7 +124,7 @@ module LocalFlow {
     exists(CfgNodes::ExprCfgNode e |
       e = nodeFrom.(AstNode).getCfgNode() and
       isReturned(e) and
-      e.getScope() = nodeTo.(PreReturNodeImpl).getCfgScope()
+      e.getScope() = nodeTo.(PreReturnNodeImpl).getCfgScope()
     )
     or
     exists(CfgNode cfgNode |
@@ -135,6 +144,14 @@ module LocalFlow {
       not blockMayReturnMultipleValues(scriptBlock) and
       nodeTo.(ReturnNodeImpl).getCfgScope() = scriptBlock.getAstNode()
     )
+    or
+    exists(CfgNodes::ExprNodes::PipelineArgumentCfgNode e | nodeFrom.asExpr() = e |
+      // If we are not already tracking as element content
+      nodeTo = TPrePipelineArgumentNode(e)
+      or
+      // If we are already tracking an element content
+      nodeTo = TPipelineArgumentNode(e)
+    )
   }
 
   predicate flowSummaryLocalStep(
@@ -180,7 +197,9 @@ private module Cached {
     TNormalParameterNode(SsaImpl::NormalParameter p) or
     TThisParameterNode(Method m) or
     TPipelineByPropertyNameParameterNode(PipelineByPropertyNameParameter p) or
-    TPipelineParamaterNode(PipelineParameter p) or
+    TPipelineParameterNode(PipelineParameter p) or
+    TPrePipelineArgumentNode(CfgNodes::ExprNodes::PipelineArgumentCfgNode n) or
+    TPipelineArgumentNode(CfgNodes::ExprNodes::PipelineArgumentCfgNode n) or
     TExprPostUpdateNode(CfgNodes::ExprCfgNode n) {
       n instanceof CfgNodes::ExprNodes::ArgumentCfgNode
       or
@@ -201,7 +220,7 @@ private module Cached {
       blockMayReturnMultipleValues(scriptBlock)
     } or
     TReturnNodeImpl(CfgScope scope) or
-    TProcessNode(ProcessBlock process) or
+    TProcessNode(CfgNodes::ProcessBlockCfgNode process) or
     TProcessPropertyByNameNode(PipelineByPropertyNameIteratorVariable iter) {
       isProcessPropertyByNameNode(iter, _)
     } or
@@ -578,10 +597,10 @@ private module ParameterNodes {
     override string toStringImpl() { result = "this" }
   }
 
-  class PipelineParamaterNode extends ParameterNodeImpl, TPipelineParamaterNode {
+  class PipelineParameterNode extends ParameterNodeImpl, TPipelineParameterNode {
     private PipelineParameter parameter;
 
-    PipelineParamaterNode() { this = TPipelineParamaterNode(parameter) }
+    PipelineParameterNode() { this = TPipelineParameterNode(parameter) }
 
     override PipelineParameter getParameter() { result = parameter }
 
@@ -671,6 +690,22 @@ abstract class ArgumentNode extends Node {
   final DataFlowCall getCall() { this.argumentOf(result, _) }
 }
 
+class PrePipelineArgumentNodeImpl extends NodeImpl, TPrePipelineArgumentNode {
+  CfgNodes::ExprNodes::PipelineArgumentCfgNode e;
+
+  PrePipelineArgumentNodeImpl() { this = TPrePipelineArgumentNode(e) }
+
+  final override CfgScope getCfgScope() { result = e.getScope() }
+
+  final override Location getLocationImpl() { result = e.getLocation() }
+
+  final override string toStringImpl() { result = "[pre pipeline] " + e.toString() }
+
+  final override predicate nodeIsHidden() { any() }
+
+  CfgNodes::ExprNodes::PipelineArgumentCfgNode getPipelineArgument() { result = e }
+}
+
 module ArgumentNodes {
   class ExplicitArgumentNode extends ArgumentNode {
     CfgNodes::ExprNodes::ArgumentCfgNode arg;
@@ -714,18 +749,23 @@ module ArgumentNodes {
     }
   }
 
-  private predicate isPipelineInput(CfgNodes::ExprCfgNode input, CfgNodes::ExprCfgNode consumer) {
-    exists(CfgNodes::ExprNodes::PipelineCfgNode pipeline, int i |
-      input = pipeline.getComponent(i) and
-      consumer = pipeline.getComponent(i + 1)
-    )
-  }
+  class PipelineArgumentNodeImpl extends NodeImpl, TPipelineArgumentNode {
+    CfgNodes::ExprNodes::PipelineArgumentCfgNode e;
 
-  class PipelineArgumentNode extends ArgumentNode, ExprNode {
-    CfgNodes::ExprCfgNode consumer;
+    PipelineArgumentNodeImpl() { this = TPipelineArgumentNode(e) }
 
-    PipelineArgumentNode() { isPipelineInput(this.getExprNode(), consumer) }
+    final override CfgScope getCfgScope() { result = e.getScope() }
 
+    final override Location getLocationImpl() { result = e.getLocation() }
+
+    final override string toStringImpl() { result = e.toString() }
+
+    final override predicate nodeIsHidden() { none() }
+
+    CfgNodes::ExprNodes::PipelineArgumentCfgNode getPipelineArgument() { result = e }
+  }
+
+  class PipelineArgumentNode extends ArgumentNode instanceof PipelineArgumentNodeImpl {
     override predicate argumentOf(DataFlowCall call, ArgumentPosition pos) {
       this.sourceArgumentOf(call.asCall(), pos)
     }
@@ -733,7 +773,7 @@ module ArgumentNodes {
     override predicate sourceArgumentOf(
       CfgNodes::ExprNodes::CallExprCfgNode call, ArgumentPosition pos
     ) {
-      call = consumer and
+      call = super.getPipelineArgument().getCall() and
       pos.isPipeline()
     }
   }
@@ -921,6 +961,12 @@ predicate storeStep(Node node1, ContentSet c, Node node2) {
     node2.(ReturnNodeImpl).getCfgScope() = cfgNode.getScope()
   )
   or
+  c.isAnyElement() and
+  exists(CfgNodes::ExprNodes::PipelineArgumentCfgNode arg |
+    node1 = TPrePipelineArgumentNode(arg) and
+    node2 = TPipelineArgumentNode(arg)
+  )
+  or
   FlowSummaryImpl::Private::Steps::summaryStoreStep(node1.(FlowSummaryNode).getSummaryNode(), c,
     node2.(FlowSummaryNode).getSummaryNode())
 }
@@ -957,14 +1003,9 @@ predicate readStep(Node node1, ContentSet c, Node node2) {
   )
   or
   c.isAnyElement() and
-  exists(SsaImpl::DefinitionExt def, ProcessNode processNode, Variable iterator |
-    processNode = node1 and iterator = def.getSourceVariable()
-  |
-    processNode.getIteratorVariable() = iterator and
-    SsaImpl::firstRead(def, node2.asExpr())
-    or
-    processNode.getPropertyNameIteratorVariable() = iterator and
-    node2 = TProcessPropertyByNameNode(def.getSourceVariable())
+  exists(CfgNodes::ProcessBlockCfgNode processBlock |
+    processBlock.getPipelineVariableAccess() = node1.asExpr() and
+    node2 = TProcessNode(processBlock)
   )
   or
   exists(
@@ -1001,6 +1042,9 @@ predicate clearsContent(Node n, ContentSet c) {
   or
   n = TPreReturnNodeImpl(_, false) and
   c.isAnyElement()
+  or
+  n instanceof PrePipelineArgumentNodeImpl and
+  c.isAnyElement()
 }
 
 /**
@@ -1016,7 +1060,7 @@ predicate expectsContent(Node n, ContentSet c) {
   n = TImplicitWrapNode(_, false) and
   c.isSingleton(any(Content::UnknownElementContent ec))
   or
-  n instanceof ProcessNode and
+  n instanceof PipelineArgumentNode and
   c.isAnyElement()
 }
 
@@ -1115,11 +1159,11 @@ private class ImplicitWrapNode extends TImplicitWrapNode, NodeImpl {
  * A node that represents the return value before any array-unwrapping
  * has been performed.
  */
-private class PreReturNodeImpl extends TPreReturnNodeImpl, NodeImpl {
+private class PreReturnNodeImpl extends TPreReturnNodeImpl, NodeImpl {
   private CfgNodes::ScriptBlockCfgNode n;
   private boolean isArray;
 
-  PreReturNodeImpl() { this = TPreReturnNodeImpl(n, isArray) }
+  PreReturnNodeImpl() { this = TPreReturnNodeImpl(n, isArray) }
 
   CfgNodes::AstCfgNode getScriptBlock() { result = n }
 
@@ -1148,11 +1192,11 @@ private class ReturnNodeImpl extends TReturnNodeImpl, NodeImpl {
 }
 
 private class ProcessNode extends TProcessNode, NodeImpl {
-  ProcessBlock process;
+  CfgNodes::ProcessBlockCfgNode process;
 
   ProcessNode() { this = TProcessNode(process) }
 
-  override CfgScope getCfgScope() { result = process.getEnclosingScope() }
+  override CfgScope getCfgScope() { result = process.getScope() }
 
   override Location getLocationImpl() { result = process.getLocation() }
 
@@ -1160,13 +1204,11 @@ private class ProcessNode extends TProcessNode, NodeImpl {
 
   override predicate nodeIsHidden() { any() }
 
-  PipelineIteratorVariable getIteratorVariable() { result.getProcessBlock() = process }
-
-  PipelineByPropertyNameIteratorVariable getPropertyNameIteratorVariable() {
-    result.getProcessBlock() = process
+  PipelineIteratorVariable getPipelineIteratorVariable() {
+    result = process.getPipelineIteratorVariable()
   }
 
-  CfgNodes::ProcessBlockCfgNode getProcessBlock() { result.getAstNode() = process }
+  CfgNodes::ProcessBlockCfgNode getProcessBlock() { result = process }
 }
 
 private class ProcessPropertyByNameNode extends TProcessPropertyByNameNode, NodeImpl {
diff --git a/powershell/ql/lib/semmle/code/powershell/dataflow/internal/SsaImpl.qll b/powershell/ql/lib/semmle/code/powershell/dataflow/internal/SsaImpl.qll
index a1e34e36af34..507ebe7f849a 100644
--- a/powershell/ql/lib/semmle/code/powershell/dataflow/internal/SsaImpl.qll
+++ b/powershell/ql/lib/semmle/code/powershell/dataflow/internal/SsaImpl.qll
@@ -30,6 +30,13 @@ module SsaInput implements SsaImplCommon::InputSig<Location> {
       uninitializedWrite(bb, i, v)
       or
       variableWriteActual(bb, i, v, _)
+      or
+      exists(ProcessBlockCfgNode processBlock |
+        bb.getNode(i) = processBlock and
+        processBlock.getPipelineIteratorVariable() = v
+      )
+      or
+      parameterWrite(bb, i, v)
     ) and
     certain = true
   }
@@ -54,7 +61,12 @@ module Consistency = Impl::Consistency;
 
 /** Holds if `v` is uninitialized at index `i` in entry block `bb`. */
 predicate uninitializedWrite(Cfg::EntryBasicBlock bb, int i, Variable v) {
-  bb.getNode(i).getAstNode() = v
+  i = -1 and
+  bb.getANode().getAstNode() = v
+}
+
+predicate parameterWrite(Cfg::EntryBasicBlock bb, int i, Parameter p) {
+  bb.getNode(i).getAstNode() = p
 }
 
 /** Holds if `v` is read at index `i` in basic block `bb`. */
@@ -288,7 +300,8 @@ class NormalParameter extends Parameter {
 
 private newtype TParameterExt =
   TNormalParameter(NormalParameter p) or
-  TThisMethodParameter(Method m)
+  TThisMethodParameter(Method m) or
+  TPipelineParameter(PipelineParameter p)
 
 /** A normal parameter or an implicit `this` parameter. */
 class ParameterExt extends TParameterExt {
@@ -296,16 +309,30 @@ class ParameterExt extends TParameterExt {
 
   Method asThis() { this = TThisMethodParameter(result) }
 
+  PipelineParameter asPipelineParameter() { this = TPipelineParameter(result) }
+
   predicate isInitializedBy(WriteDefinition def) {
     def = getParameterDef(this.asParameter())
     or
+    def = getParameterDef(this.asPipelineParameter())
+    or
     def.(Ssa::ThisDefinition).getSourceVariable().getDeclaringScope() = this.asThis().getBody()
   }
 
-  string toString() { result = [this.asParameter().toString(), this.asThis().toString()] }
+  string toString() {
+    result =
+      [
+        this.asParameter().toString(), this.asThis().toString(),
+        this.asPipelineParameter().toString()
+      ]
+  }
 
   Location getLocation() {
-    result = [this.asParameter().getLocation(), this.asThis().getLocation()]
+    result =
+      [
+        this.asParameter().getLocation(), this.asThis().getLocation(),
+        this.asPipelineParameter().getLocation()
+      ]
   }
 }
 
diff --git a/powershell/ql/test/library-tests/ast/Statements/statements.expected b/powershell/ql/test/library-tests/ast/Statements/statements.expected
index f8994f476941..6f85c09bdd1b 100644
--- a/powershell/ql/test/library-tests/ast/Statements/statements.expected
+++ b/powershell/ql/test/library-tests/ast/Statements/statements.expected
@@ -22,4 +22,4 @@
 | Try.ps1:11:9:13:1 | {...} |
 | Try.ps1:12:5:12:36 | [Stmt] The finally block is executed. |
 | UseProcessBlockForPipelineCommand.ps1:1:1:11:1 | def of Get-Number |
-| UseProcessBlockForPipelineCommand.ps1:10:5:10:11 | [Stmt] Number |
+| UseProcessBlockForPipelineCommand.ps1:10:5:10:11 | (no string representation) |
diff --git a/powershell/ql/test/library-tests/ast/parent.expected b/powershell/ql/test/library-tests/ast/parent.expected
index 13a4da5ff1c0..7fc8f9f9f727 100644
--- a/powershell/ql/test/library-tests/ast/parent.expected
+++ b/powershell/ql/test/library-tests/ast/parent.expected
@@ -328,6 +328,7 @@
 | Statements/TrapStatement.ps1:1:1:4:1 | def of TrapTest | Statements/TrapStatement.ps1:1:1:6:8 | {...} |
 | Statements/TrapStatement.ps1:1:1:6:8 | {...} | Statements/TrapStatement.ps1:1:1:6:8 | {...} |
 | Statements/TrapStatement.ps1:1:1:6:8 | {...} | file://:0:0:0:0 | toplevel function for TrapStatement.ps1 |
+| Statements/TrapStatement.ps1:1:19:4:1 | [synth] pipeline | Statements/TrapStatement.ps1:1:19:4:1 | {...} |
 | Statements/TrapStatement.ps1:1:19:4:1 | {...} | Statements/TrapStatement.ps1:1:1:4:1 | TrapTest |
 | Statements/TrapStatement.ps1:2:5:2:25 | trap {...} | Statements/TrapStatement.ps1:2:5:3:18 | {...} |
 | Statements/TrapStatement.ps1:2:5:3:18 | {...} | Statements/TrapStatement.ps1:1:19:4:1 | {...} |
@@ -375,14 +376,12 @@
 | Statements/UseProcessBlockForPipelineCommand.ps1:1:1:11:1 | def of Get-Number | Statements/UseProcessBlockForPipelineCommand.ps1:1:1:11:1 | {...} |
 | Statements/UseProcessBlockForPipelineCommand.ps1:1:1:11:1 | {...} | Statements/UseProcessBlockForPipelineCommand.ps1:1:1:11:1 | {...} |
 | Statements/UseProcessBlockForPipelineCommand.ps1:1:1:11:1 | {...} | file://:0:0:0:0 | toplevel function for UseProcessBlockForPipelineCommand.ps1 |
-| Statements/UseProcessBlockForPipelineCommand.ps1:2:1:11:1 | Number | Statements/UseProcessBlockForPipelineCommand.ps1:2:1:11:1 | {...} |
 | Statements/UseProcessBlockForPipelineCommand.ps1:2:1:11:1 | [synth] pipeline | Statements/UseProcessBlockForPipelineCommand.ps1:2:1:11:1 | {...} |
 | Statements/UseProcessBlockForPipelineCommand.ps1:2:1:11:1 | {...} | Statements/UseProcessBlockForPipelineCommand.ps1:1:1:11:1 | Get-Number |
 | Statements/UseProcessBlockForPipelineCommand.ps1:3:5:3:21 | CmdletBinding | Statements/UseProcessBlockForPipelineCommand.ps1:2:1:11:1 | {...} |
 | Statements/UseProcessBlockForPipelineCommand.ps1:4:5:10:11 | {...} | Statements/UseProcessBlockForPipelineCommand.ps1:2:1:11:1 | {...} |
-| Statements/UseProcessBlockForPipelineCommand.ps1:5:9:5:38 | ValueFromPipeline | Statements/UseProcessBlockForPipelineCommand.ps1:2:1:11:1 | Number |
+| Statements/UseProcessBlockForPipelineCommand.ps1:5:9:5:38 | ValueFromPipeline | Statements/UseProcessBlockForPipelineCommand.ps1:2:1:11:1 | [synth] pipeline |
 | Statements/UseProcessBlockForPipelineCommand.ps1:5:20:5:36 | (no string representation) | Statements/UseProcessBlockForPipelineCommand.ps1:5:20:5:36 | ValueFromPipeline |
 | Statements/UseProcessBlockForPipelineCommand.ps1:5:20:5:36 | ValueFromPipeline | Statements/UseProcessBlockForPipelineCommand.ps1:5:9:5:38 | ValueFromPipeline |
-| Statements/UseProcessBlockForPipelineCommand.ps1:6:9:6:13 | int | Statements/UseProcessBlockForPipelineCommand.ps1:2:1:11:1 | Number |
-| Statements/UseProcessBlockForPipelineCommand.ps1:10:5:10:11 | Number | Statements/UseProcessBlockForPipelineCommand.ps1:10:5:10:11 | [Stmt] Number |
-| Statements/UseProcessBlockForPipelineCommand.ps1:10:5:10:11 | [Stmt] Number | Statements/UseProcessBlockForPipelineCommand.ps1:4:5:10:11 | {...} |
+| Statements/UseProcessBlockForPipelineCommand.ps1:6:9:6:13 | int | Statements/UseProcessBlockForPipelineCommand.ps1:2:1:11:1 | [synth] pipeline |
+| Statements/UseProcessBlockForPipelineCommand.ps1:10:5:10:11 | (no string representation) | Statements/UseProcessBlockForPipelineCommand.ps1:4:5:10:11 | {...} |
diff --git a/powershell/ql/test/library-tests/controlflow/graph/Cfg.expected b/powershell/ql/test/library-tests/controlflow/graph/Cfg.expected
index d4be5cad40bf..ea88eea58ae6 100644
--- a/powershell/ql/test/library-tests/controlflow/graph/Cfg.expected
+++ b/powershell/ql/test/library-tests/controlflow/graph/Cfg.expected
@@ -153,9 +153,10 @@
 | conditionals.ps1:97:9:97:17 | return ... | conditionals.ps1:97:16:97:17 | 12 |  |
 | conditionals.ps1:97:16:97:17 | 12 | conditionals.ps1:87:5:98:5 | if (...) {...} else {...} |  |
 | conditionals.ps1:101:1:108:1 | def of test-switch | conditionals.ps1:110:1:121:1 | def of test-switch-default |  |
+| conditionals.ps1:101:26:108:1 | [synth] pipeline | conditionals.ps1:102:5:107:5 | {...} |  |
 | conditionals.ps1:101:26:108:1 | enter {...} | conditionals.ps1:101:26:108:1 | {...} |  |
 | conditionals.ps1:101:26:108:1 | exit {...} (normal) | conditionals.ps1:101:26:108:1 | exit {...} |  |
-| conditionals.ps1:101:26:108:1 | n | conditionals.ps1:102:5:107:5 | {...} |  |
+| conditionals.ps1:101:26:108:1 | n | conditionals.ps1:101:26:108:1 | [synth] pipeline |  |
 | conditionals.ps1:101:26:108:1 | {...} | conditionals.ps1:101:26:108:1 | n |  |
 | conditionals.ps1:102:5:107:5 | switch(...) {...} | conditionals.ps1:102:12:102:13 | n |  |
 | conditionals.ps1:102:5:107:5 | {...} | conditionals.ps1:102:5:107:5 | switch(...) {...} |  |
@@ -176,9 +177,10 @@
 | conditionals.ps1:106:14:106:21 | return ... | conditionals.ps1:106:21:106:21 | 2 |  |
 | conditionals.ps1:106:21:106:21 | 2 | conditionals.ps1:101:26:108:1 | exit {...} (normal) |  |
 | conditionals.ps1:110:1:121:1 | def of test-switch-default | conditionals.ps1:123:1:129:1 | def of test-switch-assign |  |
+| conditionals.ps1:110:34:121:1 | [synth] pipeline | conditionals.ps1:111:5:120:5 | {...} |  |
 | conditionals.ps1:110:34:121:1 | enter {...} | conditionals.ps1:110:34:121:1 | {...} |  |
 | conditionals.ps1:110:34:121:1 | exit {...} (normal) | conditionals.ps1:110:34:121:1 | exit {...} |  |
-| conditionals.ps1:110:34:121:1 | n | conditionals.ps1:111:5:120:5 | {...} |  |
+| conditionals.ps1:110:34:121:1 | n | conditionals.ps1:110:34:121:1 | [synth] pipeline |  |
 | conditionals.ps1:110:34:121:1 | {...} | conditionals.ps1:110:34:121:1 | n |  |
 | conditionals.ps1:111:5:120:5 | switch(...) {...} | conditionals.ps1:111:12:111:13 | n |  |
 | conditionals.ps1:111:5:120:5 | {...} | conditionals.ps1:111:5:120:5 | switch(...) {...} |  |
@@ -208,9 +210,10 @@
 | conditionals.ps1:118:13:118:20 | return ... | conditionals.ps1:118:20:118:20 | 3 |  |
 | conditionals.ps1:118:20:118:20 | 3 | conditionals.ps1:110:34:121:1 | exit {...} (normal) |  |
 | conditionals.ps1:123:1:129:1 | def of test-switch-assign | conditionals.ps1:1:1:129:1 | exit {...} (normal) |  |
+| conditionals.ps1:123:33:129:1 | [synth] pipeline | conditionals.ps1:124:5:128:5 | {...} |  |
 | conditionals.ps1:123:33:129:1 | enter {...} | conditionals.ps1:123:33:129:1 | {...} |  |
 | conditionals.ps1:123:33:129:1 | exit {...} (normal) | conditionals.ps1:123:33:129:1 | exit {...} |  |
-| conditionals.ps1:123:33:129:1 | n | conditionals.ps1:124:5:128:5 | {...} |  |
+| conditionals.ps1:123:33:129:1 | n | conditionals.ps1:123:33:129:1 | [synth] pipeline |  |
 | conditionals.ps1:123:33:129:1 | {...} | conditionals.ps1:123:33:129:1 | n |  |
 | conditionals.ps1:124:5:124:6 | a | conditionals.ps1:123:33:129:1 | exit {...} (normal) |  |
 | conditionals.ps1:124:5:128:5 | ...=... | conditionals.ps1:124:5:124:6 | a |  |
@@ -227,13 +230,9 @@
 | functions.ps1:1:32:9:1 | number2 | functions.ps1:1:32:9:1 | [synth] pipeline |  |
 | functions.ps1:1:32:9:1 | {...} | functions.ps1:1:32:9:1 | number1 |  |
 | functions.ps1:3:5:8:23 | {...} | functions.ps1:8:5:8:23 | [Stmt] ...+... |  |
-| functions.ps1:3:5:8:23 | {...} | functions.ps1:8:5:8:23 | [Stmt] __pipeline_iterator |  |
 | functions.ps1:8:5:8:12 | number1 | functions.ps1:8:16:8:23 | number2 |  |
 | functions.ps1:8:5:8:23 | ...+... | functions.ps1:1:32:9:1 | exit {...} (normal) |  |
 | functions.ps1:8:5:8:23 | [Stmt] ...+... | functions.ps1:8:5:8:12 | number1 |  |
-| functions.ps1:8:5:8:23 | [Stmt] ...+... | functions.ps1:46:17:46:18 | __pipeline_iterator |  |
-| functions.ps1:8:5:8:23 | [Stmt] __pipeline_iterator | functions.ps1:8:5:8:12 | number1 |  |
-| functions.ps1:8:5:8:23 | [Stmt] __pipeline_iterator | functions.ps1:46:17:46:18 | __pipeline_iterator |  |
 | functions.ps1:8:16:8:23 | number2 | functions.ps1:8:5:8:23 | ...+... |  |
 | functions.ps1:11:1:11:28 | def of foo | functions.ps1:13:1:20:1 | def of Default-Arguments |  |
 | functions.ps1:11:16:11:28 | [synth] pipeline | functions.ps1:11:18:11:26 | {...} |  |
@@ -253,7 +252,6 @@
 | functions.ps1:13:28:20:1 | name2 | functions.ps1:17:24:17:29 | name1 |  |
 | functions.ps1:13:28:20:1 | {...} | functions.ps1:16:24:16:24 | 0 |  |
 | functions.ps1:14:5:19:18 | {...} | functions.ps1:19:5:19:18 | [Stmt] ...+... |  |
-| functions.ps1:14:5:19:18 | {...} | functions.ps1:19:5:19:18 | [Stmt] __pipeline_iterator |  |
 | functions.ps1:16:24:16:24 | 0 | functions.ps1:13:28:20:1 | name2 |  |
 | functions.ps1:16:24:16:24 | 0 | functions.ps1:17:24:17:29 | name1 |  |
 | functions.ps1:17:24:17:29 | name1 | functions.ps1:17:33:17:33 | 1 |  |
@@ -262,9 +260,6 @@
 | functions.ps1:17:33:17:33 | 1 | functions.ps1:17:24:17:33 | ...+... |  |
 | functions.ps1:19:5:19:18 | ...+... | functions.ps1:13:28:20:1 | exit {...} (normal) |  |
 | functions.ps1:19:5:19:18 | [Stmt] ...+... | functions.ps1:19:13:19:18 | name2 |  |
-| functions.ps1:19:5:19:18 | [Stmt] ...+... | functions.ps1:46:17:46:18 | __pipeline_iterator |  |
-| functions.ps1:19:5:19:18 | [Stmt] __pipeline_iterator | functions.ps1:19:13:19:18 | name2 |  |
-| functions.ps1:19:5:19:18 | [Stmt] __pipeline_iterator | functions.ps1:46:17:46:18 | __pipeline_iterator |  |
 | functions.ps1:19:13:19:18 | name2 | functions.ps1:19:5:19:18 | ...+... |  |
 | functions.ps1:22:1:34:1 | def of Add-Numbers-From-Array | functions.ps1:36:1:52:1 | def of Add-Numbers-From-Pipeline |  |
 | functions.ps1:22:33:34:1 | [synth] pipeline | functions.ps1:24:5:33:8 | {...} |  |
@@ -276,13 +271,9 @@
 | functions.ps1:28:5:28:8 | sum | functions.ps1:28:12:28:12 | 0 |  |
 | functions.ps1:28:5:28:12 | ...=... | functions.ps1:28:5:28:8 | sum |  |
 | functions.ps1:28:12:28:12 | 0 | functions.ps1:29:25:29:32 | numbers |  |
-| functions.ps1:29:5:32:5 | forach(... in ...) | functions.ps1:33:5:33:8 | [Stmt] __pipeline_iterator | empty |
 | functions.ps1:29:5:32:5 | forach(... in ...) | functions.ps1:33:5:33:8 | [Stmt] sum | empty |
 | functions.ps1:29:25:29:32 | numbers | functions.ps1:29:5:32:5 | forach(... in ...) |  |
-| functions.ps1:33:5:33:8 | [Stmt] __pipeline_iterator | functions.ps1:33:5:33:8 | sum |  |
-| functions.ps1:33:5:33:8 | [Stmt] __pipeline_iterator | functions.ps1:46:17:46:18 | __pipeline_iterator |  |
 | functions.ps1:33:5:33:8 | [Stmt] sum | functions.ps1:33:5:33:8 | sum |  |
-| functions.ps1:33:5:33:8 | [Stmt] sum | functions.ps1:46:17:46:18 | __pipeline_iterator |  |
 | functions.ps1:33:5:33:8 | sum | functions.ps1:22:33:34:1 | exit {...} (normal) |  |
 | functions.ps1:36:1:52:1 | def of Add-Numbers-From-Pipeline | functions.ps1:1:1:54:0 | exit {...} (normal) |  |
 | functions.ps1:36:36:52:1 | [synth] pipeline | functions.ps1:41:5:43:5 | {...} |  |
@@ -293,20 +284,14 @@
 | functions.ps1:41:5:43:5 | {...} | functions.ps1:42:9:42:16 | ...=... |  |
 | functions.ps1:42:9:42:12 | sum | functions.ps1:42:16:42:16 | 0 |  |
 | functions.ps1:42:9:42:16 | ...=... | functions.ps1:42:9:42:12 | sum |  |
-| functions.ps1:42:16:42:16 | 0 | functions.ps1:44:5:47:5 | {...} |  |
+| functions.ps1:42:16:42:16 | 0 | functions.ps1:44:5:47:5 | [synth] pipeline |  |
+| functions.ps1:44:5:47:5 | [synth] pipeline | functions.ps1:44:5:47:5 | {...} |  |
 | functions.ps1:44:5:47:5 | {...} | functions.ps1:46:9:46:18 | ...=... |  |
-| functions.ps1:46:9:46:12 | sum | functions.ps1:44:5:47:5 | {...} |  |
-| functions.ps1:46:9:46:12 | sum | functions.ps1:48:5:51:5 | {...} |  |
+| functions.ps1:46:9:46:12 | sum | functions.ps1:46:17:46:18 | __pipeline_iterator |  |
 | functions.ps1:46:9:46:18 | ...=... | functions.ps1:46:9:46:12 | sum |  |
-| functions.ps1:46:17:46:18 | __pipeline_iterator | functions.ps1:1:32:9:1 | exit {...} (normal) |  |
-| functions.ps1:46:17:46:18 | __pipeline_iterator | functions.ps1:13:28:20:1 | exit {...} (normal) |  |
-| functions.ps1:46:17:46:18 | __pipeline_iterator | functions.ps1:22:33:34:1 | exit {...} (normal) |  |
-| functions.ps1:46:17:46:18 | __pipeline_iterator | functions.ps1:36:36:52:1 | exit {...} (normal) |  |
-| functions.ps1:48:5:51:5 | {...} | functions.ps1:50:9:50:12 | [Stmt] __pipeline_iterator |  |
+| functions.ps1:46:17:46:18 | __pipeline_iterator | functions.ps1:44:5:47:5 | [synth] pipeline |  |
+| functions.ps1:46:17:46:18 | __pipeline_iterator | functions.ps1:48:5:51:5 | {...} |  |
 | functions.ps1:48:5:51:5 | {...} | functions.ps1:50:9:50:12 | [Stmt] sum |  |
-| functions.ps1:50:9:50:12 | [Stmt] __pipeline_iterator | functions.ps1:46:17:46:18 | __pipeline_iterator |  |
-| functions.ps1:50:9:50:12 | [Stmt] __pipeline_iterator | functions.ps1:50:9:50:12 | sum |  |
-| functions.ps1:50:9:50:12 | [Stmt] sum | functions.ps1:46:17:46:18 | __pipeline_iterator |  |
 | functions.ps1:50:9:50:12 | [Stmt] sum | functions.ps1:50:9:50:12 | sum |  |
 | functions.ps1:50:9:50:12 | sum | functions.ps1:36:36:52:1 | exit {...} (normal) |  |
 | global.ps1:1:1:4:1 | {...} | global.ps1:2:5:2:10 | ...=... |  |
@@ -330,9 +315,10 @@
 | loops.ps1:1:1:70:0 | enter {...} | loops.ps1:1:1:70:0 | {...} |  |
 | loops.ps1:1:1:70:0 | exit {...} (normal) | loops.ps1:1:1:70:0 | exit {...} |  |
 | loops.ps1:1:1:70:0 | {...} | loops.ps1:1:1:68:1 | {...} |  |
+| loops.ps1:1:21:7:1 | [synth] pipeline | loops.ps1:2:5:6:5 | {...} |  |
 | loops.ps1:1:21:7:1 | enter {...} | loops.ps1:1:21:7:1 | {...} |  |
 | loops.ps1:1:21:7:1 | exit {...} (normal) | loops.ps1:1:21:7:1 | exit {...} |  |
-| loops.ps1:1:21:7:1 | {...} | loops.ps1:2:5:6:5 | {...} |  |
+| loops.ps1:1:21:7:1 | {...} | loops.ps1:1:21:7:1 | [synth] pipeline |  |
 | loops.ps1:2:5:2:6 | a | loops.ps1:2:10:2:10 | 0 |  |
 | loops.ps1:2:5:2:10 | ...=... | loops.ps1:2:5:2:6 | a |  |
 | loops.ps1:2:5:6:5 | {...} | loops.ps1:2:5:2:10 | ...=... |  |
@@ -349,9 +335,10 @@
 | loops.ps1:5:14:5:19 | ...+... | loops.ps1:4:11:4:12 | a |  |
 | loops.ps1:5:19:5:19 | 1 | loops.ps1:5:14:5:19 | ...+... |  |
 | loops.ps1:9:1:15:1 | def of Test-Break | loops.ps1:17:1:23:1 | def of Test-Continue |  |
+| loops.ps1:9:21:15:1 | [synth] pipeline | loops.ps1:10:5:14:5 | {...} |  |
 | loops.ps1:9:21:15:1 | enter {...} | loops.ps1:9:21:15:1 | {...} |  |
 | loops.ps1:9:21:15:1 | exit {...} (normal) | loops.ps1:9:21:15:1 | exit {...} |  |
-| loops.ps1:9:21:15:1 | {...} | loops.ps1:10:5:14:5 | {...} |  |
+| loops.ps1:9:21:15:1 | {...} | loops.ps1:9:21:15:1 | [synth] pipeline |  |
 | loops.ps1:10:5:10:6 | a | loops.ps1:10:10:10:10 | 0 |  |
 | loops.ps1:10:5:10:10 | ...=... | loops.ps1:10:5:10:6 | a |  |
 | loops.ps1:10:5:14:5 | {...} | loops.ps1:10:5:10:10 | ...=... |  |
@@ -364,9 +351,10 @@
 | loops.ps1:11:22:14:5 | {...} | loops.ps1:12:9:12:13 | break |  |
 | loops.ps1:12:9:12:13 | break | loops.ps1:9:21:15:1 | exit {...} (normal) | break |
 | loops.ps1:17:1:23:1 | def of Test-Continue | loops.ps1:25:1:31:1 | def of Test-DoWhile |  |
+| loops.ps1:17:24:23:1 | [synth] pipeline | loops.ps1:18:5:22:5 | {...} |  |
 | loops.ps1:17:24:23:1 | enter {...} | loops.ps1:17:24:23:1 | {...} |  |
 | loops.ps1:17:24:23:1 | exit {...} (normal) | loops.ps1:17:24:23:1 | exit {...} |  |
-| loops.ps1:17:24:23:1 | {...} | loops.ps1:18:5:22:5 | {...} |  |
+| loops.ps1:17:24:23:1 | {...} | loops.ps1:17:24:23:1 | [synth] pipeline |  |
 | loops.ps1:18:5:18:6 | a | loops.ps1:18:10:18:10 | 0 |  |
 | loops.ps1:18:5:18:10 | ...=... | loops.ps1:18:5:18:6 | a |  |
 | loops.ps1:18:5:22:5 | {...} | loops.ps1:18:5:18:10 | ...=... |  |
@@ -379,9 +367,10 @@
 | loops.ps1:19:22:22:5 | {...} | loops.ps1:20:9:20:16 | continue |  |
 | loops.ps1:20:9:20:16 | continue | loops.ps1:19:11:19:12 | a | continue |
 | loops.ps1:25:1:31:1 | def of Test-DoWhile | loops.ps1:33:1:39:1 | def of Test-DoUntil |  |
+| loops.ps1:25:23:31:1 | [synth] pipeline | loops.ps1:26:5:30:23 | {...} |  |
 | loops.ps1:25:23:31:1 | enter {...} | loops.ps1:25:23:31:1 | {...} |  |
 | loops.ps1:25:23:31:1 | exit {...} (normal) | loops.ps1:25:23:31:1 | exit {...} |  |
-| loops.ps1:25:23:31:1 | {...} | loops.ps1:26:5:30:23 | {...} |  |
+| loops.ps1:25:23:31:1 | {...} | loops.ps1:25:23:31:1 | [synth] pipeline |  |
 | loops.ps1:26:5:26:6 | a | loops.ps1:26:10:26:10 | 0 |  |
 | loops.ps1:26:5:26:10 | ...=... | loops.ps1:26:5:26:6 | a |  |
 | loops.ps1:26:5:30:23 | {...} | loops.ps1:26:5:26:10 | ...=... |  |
@@ -398,9 +387,10 @@
 | loops.ps1:30:14:30:22 | ... -le ... | loops.ps1:28:8:30:5 | {...} | true |
 | loops.ps1:30:21:30:22 | 10 | loops.ps1:30:14:30:22 | ... -le ... |  |
 | loops.ps1:33:1:39:1 | def of Test-DoUntil | loops.ps1:41:1:47:1 | def of Test-For |  |
+| loops.ps1:33:23:39:1 | [synth] pipeline | loops.ps1:34:5:38:23 | {...} |  |
 | loops.ps1:33:23:39:1 | enter {...} | loops.ps1:33:23:39:1 | {...} |  |
 | loops.ps1:33:23:39:1 | exit {...} (normal) | loops.ps1:33:23:39:1 | exit {...} |  |
-| loops.ps1:33:23:39:1 | {...} | loops.ps1:34:5:38:23 | {...} |  |
+| loops.ps1:33:23:39:1 | {...} | loops.ps1:33:23:39:1 | [synth] pipeline |  |
 | loops.ps1:34:5:34:6 | a | loops.ps1:34:10:34:10 | 0 |  |
 | loops.ps1:34:5:34:10 | ...=... | loops.ps1:34:5:34:6 | a |  |
 | loops.ps1:34:5:38:23 | {...} | loops.ps1:34:5:34:10 | ...=... |  |
@@ -417,9 +407,10 @@
 | loops.ps1:38:14:38:22 | ... -ge ... | loops.ps1:36:8:38:5 | {...} | false |
 | loops.ps1:38:21:38:22 | 10 | loops.ps1:38:14:38:22 | ... -ge ... |  |
 | loops.ps1:41:1:47:1 | def of Test-For | loops.ps1:49:1:56:1 | def of Test-ForEach |  |
+| loops.ps1:41:19:47:1 | [synth] pipeline | loops.ps1:42:5:46:5 | {...} |  |
 | loops.ps1:41:19:47:1 | enter {...} | loops.ps1:41:19:47:1 | {...} |  |
 | loops.ps1:41:19:47:1 | exit {...} (normal) | loops.ps1:41:19:47:1 | exit {...} |  |
-| loops.ps1:41:19:47:1 | {...} | loops.ps1:42:5:46:5 | {...} |  |
+| loops.ps1:41:19:47:1 | {...} | loops.ps1:41:19:47:1 | [synth] pipeline |  |
 | loops.ps1:42:5:42:6 | a | loops.ps1:42:10:42:10 | 0 |  |
 | loops.ps1:42:5:42:10 | ...=... | loops.ps1:42:5:42:6 | a |  |
 | loops.ps1:42:5:46:5 | {...} | loops.ps1:42:5:42:10 | ...=... |  |
@@ -445,9 +436,10 @@
 | loops.ps1:45:14:45:19 | ...+... | loops.ps1:44:29:44:39 | ...=... |  |
 | loops.ps1:45:19:45:19 | 1 | loops.ps1:45:14:45:19 | ...+... |  |
 | loops.ps1:49:1:56:1 | def of Test-ForEach | loops.ps1:58:1:68:1 | def of Test-For-Ever |  |
+| loops.ps1:49:23:56:1 | [synth] pipeline | loops.ps1:50:5:55:5 | {...} |  |
 | loops.ps1:49:23:56:1 | enter {...} | loops.ps1:49:23:56:1 | {...} |  |
 | loops.ps1:49:23:56:1 | exit {...} (normal) | loops.ps1:49:23:56:1 | exit {...} |  |
-| loops.ps1:49:23:56:1 | {...} | loops.ps1:50:5:55:5 | {...} |  |
+| loops.ps1:49:23:56:1 | {...} | loops.ps1:49:23:56:1 | [synth] pipeline |  |
 | loops.ps1:50:5:50:16 | letterArray | loops.ps1:50:20:50:22 | a |  |
 | loops.ps1:50:5:50:34 | ...=... | loops.ps1:50:5:50:16 | letterArray |  |
 | loops.ps1:50:5:55:5 | {...} | loops.ps1:50:5:50:34 | ...=... |  |
@@ -462,9 +454,10 @@
 | loops.ps1:52:5:55:5 | forach(... in ...) | loops.ps1:49:23:56:1 | exit {...} (normal) | empty |
 | loops.ps1:52:25:52:36 | letterArray | loops.ps1:52:5:55:5 | forach(... in ...) |  |
 | loops.ps1:58:1:68:1 | def of Test-For-Ever | loops.ps1:1:1:70:0 | exit {...} (normal) |  |
+| loops.ps1:58:24:68:1 | [synth] pipeline | loops.ps1:59:5:67:5 | {...} |  |
 | loops.ps1:58:24:68:1 | enter {...} | loops.ps1:58:24:68:1 | {...} |  |
 | loops.ps1:58:24:68:1 | exit {...} (normal) | loops.ps1:58:24:68:1 | exit {...} |  |
-| loops.ps1:58:24:68:1 | {...} | loops.ps1:59:5:67:5 | {...} |  |
+| loops.ps1:58:24:68:1 | {...} | loops.ps1:58:24:68:1 | [synth] pipeline |  |
 | loops.ps1:59:5:59:6 | a | loops.ps1:59:10:59:10 | 0 |  |
 | loops.ps1:59:5:59:10 | ...=... | loops.ps1:59:5:59:6 | a |  |
 | loops.ps1:59:5:67:5 | {...} | loops.ps1:59:5:59:10 | ...=... |  |
@@ -484,9 +477,10 @@
 | try.ps1:1:1:194:1 | exit {...} (normal) | try.ps1:1:1:194:1 | exit {...} |  |
 | try.ps1:1:1:194:1 | {...} | try.ps1:1:1:8:1 | def of test-try-catch |  |
 | try.ps1:1:1:194:1 | {...} | try.ps1:1:1:194:1 | {...} |  |
+| try.ps1:1:25:8:1 | [synth] pipeline | try.ps1:2:5:7:12 | {...} |  |
 | try.ps1:1:25:8:1 | enter {...} | try.ps1:1:25:8:1 | {...} |  |
 | try.ps1:1:25:8:1 | exit {...} (normal) | try.ps1:1:25:8:1 | exit {...} |  |
-| try.ps1:1:25:8:1 | {...} | try.ps1:2:5:7:12 | {...} |  |
+| try.ps1:1:25:8:1 | {...} | try.ps1:1:25:8:1 | [synth] pipeline |  |
 | try.ps1:2:5:6:5 | try {...} | try.ps1:2:9:4:5 | {...} |  |
 | try.ps1:2:5:7:12 | {...} | try.ps1:2:5:6:5 | try {...} |  |
 | try.ps1:2:9:4:5 | {...} | try.ps1:3:9:3:29 | [Stmt] Call to Write-Output |  |
@@ -497,7 +491,8 @@
 | try.ps1:7:5:7:12 | return ... | try.ps1:7:12:7:12 | 1 |  |
 | try.ps1:7:12:7:12 | 1 | try.ps1:1:25:8:1 | exit {...} (normal) |  |
 | try.ps1:10:1:19:1 | def of test-try-with-throw-catch | try.ps1:21:1:30:1 | def of test-try-with-throw-catch-with-throw |  |
-| try.ps1:10:40:19:1 | b | try.ps1:11:5:18:12 | {...} |  |
+| try.ps1:10:40:19:1 | [synth] pipeline | try.ps1:11:5:18:12 | {...} |  |
+| try.ps1:10:40:19:1 | b | try.ps1:10:40:19:1 | [synth] pipeline |  |
 | try.ps1:10:40:19:1 | enter {...} | try.ps1:10:40:19:1 | {...} |  |
 | try.ps1:10:40:19:1 | exit {...} (normal) | try.ps1:10:40:19:1 | exit {...} |  |
 | try.ps1:10:40:19:1 | {...} | try.ps1:10:40:19:1 | b |  |
@@ -514,7 +509,8 @@
 | try.ps1:18:5:18:12 | return ... | try.ps1:18:12:18:12 | 1 |  |
 | try.ps1:18:12:18:12 | 1 | try.ps1:10:40:19:1 | exit {...} (normal) |  |
 | try.ps1:21:1:30:1 | def of test-try-with-throw-catch-with-throw | try.ps1:32:1:41:1 | def of test-try-with-throw-catch-with-rethrow |  |
-| try.ps1:21:51:30:1 | b | try.ps1:22:5:29:12 | {...} |  |
+| try.ps1:21:51:30:1 | [synth] pipeline | try.ps1:22:5:29:12 | {...} |  |
+| try.ps1:21:51:30:1 | b | try.ps1:21:51:30:1 | [synth] pipeline |  |
 | try.ps1:21:51:30:1 | enter {...} | try.ps1:21:51:30:1 | {...} |  |
 | try.ps1:21:51:30:1 | exit {...} (normal) | try.ps1:21:51:30:1 | exit {...} |  |
 | try.ps1:21:51:30:1 | {...} | try.ps1:21:51:30:1 | b |  |
@@ -531,7 +527,8 @@
 | try.ps1:29:5:29:12 | return ... | try.ps1:29:12:29:12 | 1 |  |
 | try.ps1:29:12:29:12 | 1 | try.ps1:21:51:30:1 | exit {...} (normal) |  |
 | try.ps1:32:1:41:1 | def of test-try-with-throw-catch-with-rethrow | try.ps1:43:1:50:1 | def of test-try-catch-specific-1 |  |
-| try.ps1:32:53:41:1 | b | try.ps1:33:5:40:12 | {...} |  |
+| try.ps1:32:53:41:1 | [synth] pipeline | try.ps1:33:5:40:12 | {...} |  |
+| try.ps1:32:53:41:1 | b | try.ps1:32:53:41:1 | [synth] pipeline |  |
 | try.ps1:32:53:41:1 | enter {...} | try.ps1:32:53:41:1 | {...} |  |
 | try.ps1:32:53:41:1 | exit {...} (normal) | try.ps1:32:53:41:1 | exit {...} |  |
 | try.ps1:32:53:41:1 | {...} | try.ps1:32:53:41:1 | b |  |
@@ -548,9 +545,10 @@
 | try.ps1:40:5:40:12 | return ... | try.ps1:40:12:40:12 | 1 |  |
 | try.ps1:40:12:40:12 | 1 | try.ps1:32:53:41:1 | exit {...} (normal) |  |
 | try.ps1:43:1:50:1 | def of test-try-catch-specific-1 | try.ps1:52:1:59:1 | def of test-try-catch-specific-1 |  |
+| try.ps1:43:36:50:1 | [synth] pipeline | try.ps1:44:5:49:12 | {...} |  |
 | try.ps1:43:36:50:1 | enter {...} | try.ps1:43:36:50:1 | {...} |  |
 | try.ps1:43:36:50:1 | exit {...} (normal) | try.ps1:43:36:50:1 | exit {...} |  |
-| try.ps1:43:36:50:1 | {...} | try.ps1:44:5:49:12 | {...} |  |
+| try.ps1:43:36:50:1 | {...} | try.ps1:43:36:50:1 | [synth] pipeline |  |
 | try.ps1:44:5:48:5 | try {...} | try.ps1:44:9:46:5 | {...} |  |
 | try.ps1:44:5:49:12 | {...} | try.ps1:44:5:48:5 | try {...} |  |
 | try.ps1:44:9:46:5 | {...} | try.ps1:45:9:45:29 | [Stmt] Call to Write-Output |  |
@@ -561,9 +559,10 @@
 | try.ps1:49:5:49:12 | return ... | try.ps1:49:12:49:12 | 1 |  |
 | try.ps1:49:12:49:12 | 1 | try.ps1:43:36:50:1 | exit {...} (normal) |  |
 | try.ps1:52:1:59:1 | def of test-try-catch-specific-1 | try.ps1:61:1:70:1 | def of test-try-two-catch-specific-1 |  |
+| try.ps1:52:36:59:1 | [synth] pipeline | try.ps1:53:5:58:12 | {...} |  |
 | try.ps1:52:36:59:1 | enter {...} | try.ps1:52:36:59:1 | {...} |  |
 | try.ps1:52:36:59:1 | exit {...} (normal) | try.ps1:52:36:59:1 | exit {...} |  |
-| try.ps1:52:36:59:1 | {...} | try.ps1:53:5:58:12 | {...} |  |
+| try.ps1:52:36:59:1 | {...} | try.ps1:52:36:59:1 | [synth] pipeline |  |
 | try.ps1:53:5:57:5 | try {...} | try.ps1:53:9:55:5 | {...} |  |
 | try.ps1:53:5:58:12 | {...} | try.ps1:53:5:57:5 | try {...} |  |
 | try.ps1:53:9:55:5 | {...} | try.ps1:54:9:54:29 | [Stmt] Call to Write-Output |  |
@@ -574,9 +573,10 @@
 | try.ps1:58:5:58:12 | return ... | try.ps1:58:12:58:12 | 1 |  |
 | try.ps1:58:12:58:12 | 1 | try.ps1:52:36:59:1 | exit {...} (normal) |  |
 | try.ps1:61:1:70:1 | def of test-try-two-catch-specific-1 | try.ps1:72:1:79:1 | def of test-try-catch-specific-2 |  |
+| try.ps1:61:40:70:1 | [synth] pipeline | try.ps1:62:5:69:12 | {...} |  |
 | try.ps1:61:40:70:1 | enter {...} | try.ps1:61:40:70:1 | {...} |  |
 | try.ps1:61:40:70:1 | exit {...} (normal) | try.ps1:61:40:70:1 | exit {...} |  |
-| try.ps1:61:40:70:1 | {...} | try.ps1:62:5:69:12 | {...} |  |
+| try.ps1:61:40:70:1 | {...} | try.ps1:61:40:70:1 | [synth] pipeline |  |
 | try.ps1:62:5:68:5 | try {...} | try.ps1:62:9:64:5 | {...} |  |
 | try.ps1:62:5:69:12 | {...} | try.ps1:62:5:68:5 | try {...} |  |
 | try.ps1:62:9:64:5 | {...} | try.ps1:63:9:63:29 | [Stmt] Call to Write-Output |  |
@@ -587,9 +587,10 @@
 | try.ps1:69:5:69:12 | return ... | try.ps1:69:12:69:12 | 2 |  |
 | try.ps1:69:12:69:12 | 2 | try.ps1:61:40:70:1 | exit {...} (normal) |  |
 | try.ps1:72:1:79:1 | def of test-try-catch-specific-2 | try.ps1:81:1:90:1 | def of test-try-two-catch-specific-2 |  |
+| try.ps1:72:36:79:1 | [synth] pipeline | try.ps1:73:5:78:12 | {...} |  |
 | try.ps1:72:36:79:1 | enter {...} | try.ps1:72:36:79:1 | {...} |  |
 | try.ps1:72:36:79:1 | exit {...} (normal) | try.ps1:72:36:79:1 | exit {...} |  |
-| try.ps1:72:36:79:1 | {...} | try.ps1:73:5:78:12 | {...} |  |
+| try.ps1:72:36:79:1 | {...} | try.ps1:72:36:79:1 | [synth] pipeline |  |
 | try.ps1:73:5:77:5 | try {...} | try.ps1:73:9:75:5 | {...} |  |
 | try.ps1:73:5:78:12 | {...} | try.ps1:73:5:77:5 | try {...} |  |
 | try.ps1:73:9:75:5 | {...} | try.ps1:74:9:74:29 | [Stmt] Call to Write-Output |  |
@@ -600,9 +601,10 @@
 | try.ps1:78:5:78:12 | return ... | try.ps1:78:12:78:12 | 1 |  |
 | try.ps1:78:12:78:12 | 1 | try.ps1:72:36:79:1 | exit {...} (normal) |  |
 | try.ps1:81:1:90:1 | def of test-try-two-catch-specific-2 | try.ps1:92:1:103:1 | def of test-try-three-catch-specific-2 |  |
+| try.ps1:81:40:90:1 | [synth] pipeline | try.ps1:82:5:89:12 | {...} |  |
 | try.ps1:81:40:90:1 | enter {...} | try.ps1:81:40:90:1 | {...} |  |
 | try.ps1:81:40:90:1 | exit {...} (normal) | try.ps1:81:40:90:1 | exit {...} |  |
-| try.ps1:81:40:90:1 | {...} | try.ps1:82:5:89:12 | {...} |  |
+| try.ps1:81:40:90:1 | {...} | try.ps1:81:40:90:1 | [synth] pipeline |  |
 | try.ps1:82:5:88:5 | try {...} | try.ps1:82:9:84:5 | {...} |  |
 | try.ps1:82:5:89:12 | {...} | try.ps1:82:5:88:5 | try {...} |  |
 | try.ps1:82:9:84:5 | {...} | try.ps1:83:9:83:29 | [Stmt] Call to Write-Output |  |
@@ -613,9 +615,10 @@
 | try.ps1:89:5:89:12 | return ... | try.ps1:89:12:89:12 | 2 |  |
 | try.ps1:89:12:89:12 | 2 | try.ps1:81:40:90:1 | exit {...} (normal) |  |
 | try.ps1:92:1:103:1 | def of test-try-three-catch-specific-2 | try.ps1:105:1:114:1 | def of test-try-catch-finally |  |
+| try.ps1:92:42:103:1 | [synth] pipeline | try.ps1:93:5:102:12 | {...} |  |
 | try.ps1:92:42:103:1 | enter {...} | try.ps1:92:42:103:1 | {...} |  |
 | try.ps1:92:42:103:1 | exit {...} (normal) | try.ps1:92:42:103:1 | exit {...} |  |
-| try.ps1:92:42:103:1 | {...} | try.ps1:93:5:102:12 | {...} |  |
+| try.ps1:92:42:103:1 | {...} | try.ps1:92:42:103:1 | [synth] pipeline |  |
 | try.ps1:93:5:101:5 | try {...} | try.ps1:93:9:95:5 | {...} |  |
 | try.ps1:93:5:102:12 | {...} | try.ps1:93:5:101:5 | try {...} |  |
 | try.ps1:93:9:95:5 | {...} | try.ps1:94:9:94:29 | [Stmt] Call to Write-Output |  |
@@ -626,9 +629,10 @@
 | try.ps1:102:5:102:12 | return ... | try.ps1:102:12:102:12 | 3 |  |
 | try.ps1:102:12:102:12 | 3 | try.ps1:92:42:103:1 | exit {...} (normal) |  |
 | try.ps1:105:1:114:1 | def of test-try-catch-finally | try.ps1:116:1:123:1 | def of test-try-finally |  |
+| try.ps1:105:33:114:1 | [synth] pipeline | try.ps1:106:5:113:12 | {...} |  |
 | try.ps1:105:33:114:1 | enter {...} | try.ps1:105:33:114:1 | {...} |  |
 | try.ps1:105:33:114:1 | exit {...} (normal) | try.ps1:105:33:114:1 | exit {...} |  |
-| try.ps1:105:33:114:1 | {...} | try.ps1:106:5:113:12 | {...} |  |
+| try.ps1:105:33:114:1 | {...} | try.ps1:105:33:114:1 | [synth] pipeline |  |
 | try.ps1:106:5:112:5 | try {...} | try.ps1:106:9:108:5 | {...} |  |
 | try.ps1:106:5:113:12 | {...} | try.ps1:106:5:112:5 | try {...} |  |
 | try.ps1:106:9:108:5 | {...} | try.ps1:107:9:107:29 | [Stmt] Call to Write-Output |  |
@@ -644,9 +648,10 @@
 | try.ps1:113:5:113:12 | return ... | try.ps1:113:12:113:12 | 1 |  |
 | try.ps1:113:12:113:12 | 1 | try.ps1:105:33:114:1 | exit {...} (normal) |  |
 | try.ps1:116:1:123:1 | def of test-try-finally | try.ps1:125:1:134:1 | def of test-try-finally-catch-specific-1 |  |
+| try.ps1:116:27:123:1 | [synth] pipeline | try.ps1:117:5:122:12 | {...} |  |
 | try.ps1:116:27:123:1 | enter {...} | try.ps1:116:27:123:1 | {...} |  |
 | try.ps1:116:27:123:1 | exit {...} (normal) | try.ps1:116:27:123:1 | exit {...} |  |
-| try.ps1:116:27:123:1 | {...} | try.ps1:117:5:122:12 | {...} |  |
+| try.ps1:116:27:123:1 | {...} | try.ps1:116:27:123:1 | [synth] pipeline |  |
 | try.ps1:117:5:121:5 | try {...} | try.ps1:117:9:119:5 | {...} |  |
 | try.ps1:117:5:122:12 | {...} | try.ps1:117:5:121:5 | try {...} |  |
 | try.ps1:117:9:119:5 | {...} | try.ps1:118:9:118:29 | [Stmt] Call to Write-Output |  |
@@ -662,9 +667,10 @@
 | try.ps1:122:5:122:12 | return ... | try.ps1:122:12:122:12 | 1 |  |
 | try.ps1:122:12:122:12 | 1 | try.ps1:116:27:123:1 | exit {...} (normal) |  |
 | try.ps1:125:1:134:1 | def of test-try-finally-catch-specific-1 | try.ps1:136:1:147:1 | def of test-nested-try-inner-finally |  |
+| try.ps1:125:44:134:1 | [synth] pipeline | try.ps1:126:5:133:12 | {...} |  |
 | try.ps1:125:44:134:1 | enter {...} | try.ps1:125:44:134:1 | {...} |  |
 | try.ps1:125:44:134:1 | exit {...} (normal) | try.ps1:125:44:134:1 | exit {...} |  |
-| try.ps1:125:44:134:1 | {...} | try.ps1:126:5:133:12 | {...} |  |
+| try.ps1:125:44:134:1 | {...} | try.ps1:125:44:134:1 | [synth] pipeline |  |
 | try.ps1:126:5:132:5 | try {...} | try.ps1:126:9:128:5 | {...} |  |
 | try.ps1:126:5:133:12 | {...} | try.ps1:126:5:132:5 | try {...} |  |
 | try.ps1:126:9:128:5 | {...} | try.ps1:127:9:127:29 | [Stmt] Call to Write-Output |  |
@@ -680,9 +686,10 @@
 | try.ps1:133:5:133:12 | return ... | try.ps1:133:12:133:12 | 1 |  |
 | try.ps1:133:12:133:12 | 1 | try.ps1:125:44:134:1 | exit {...} (normal) |  |
 | try.ps1:136:1:147:1 | def of test-nested-try-inner-finally | try.ps1:149:1:162:1 | def of test-nested-try-inner-finally |  |
+| try.ps1:136:40:147:1 | [synth] pipeline | try.ps1:137:5:146:12 | {...} |  |
 | try.ps1:136:40:147:1 | enter {...} | try.ps1:136:40:147:1 | {...} |  |
 | try.ps1:136:40:147:1 | exit {...} (normal) | try.ps1:136:40:147:1 | exit {...} |  |
-| try.ps1:136:40:147:1 | {...} | try.ps1:137:5:146:12 | {...} |  |
+| try.ps1:136:40:147:1 | {...} | try.ps1:136:40:147:1 | [synth] pipeline |  |
 | try.ps1:137:5:145:5 | try {...} | try.ps1:137:9:143:5 | {...} |  |
 | try.ps1:137:5:146:12 | {...} | try.ps1:137:5:145:5 | try {...} |  |
 | try.ps1:137:9:143:5 | {...} | try.ps1:138:9:142:9 | try {...} |  |
@@ -695,9 +702,10 @@
 | try.ps1:146:5:146:12 | return ... | try.ps1:146:12:146:12 | 1 |  |
 | try.ps1:146:12:146:12 | 1 | try.ps1:136:40:147:1 | exit {...} (normal) |  |
 | try.ps1:149:1:162:1 | def of test-nested-try-inner-finally | try.ps1:164:1:177:1 | def of test-nested-try-outer-finally |  |
+| try.ps1:149:40:162:1 | [synth] pipeline | try.ps1:150:5:161:12 | {...} |  |
 | try.ps1:149:40:162:1 | enter {...} | try.ps1:149:40:162:1 | {...} |  |
 | try.ps1:149:40:162:1 | exit {...} (normal) | try.ps1:149:40:162:1 | exit {...} |  |
-| try.ps1:149:40:162:1 | {...} | try.ps1:150:5:161:12 | {...} |  |
+| try.ps1:149:40:162:1 | {...} | try.ps1:149:40:162:1 | [synth] pipeline |  |
 | try.ps1:150:5:160:5 | try {...} | try.ps1:150:9:158:5 | {...} |  |
 | try.ps1:150:5:161:12 | {...} | try.ps1:150:5:160:5 | try {...} |  |
 | try.ps1:150:9:158:5 | {...} | try.ps1:151:9:157:9 | try {...} |  |
@@ -715,9 +723,10 @@
 | try.ps1:161:5:161:12 | return ... | try.ps1:161:12:161:12 | 1 |  |
 | try.ps1:161:12:161:12 | 1 | try.ps1:149:40:162:1 | exit {...} (normal) |  |
 | try.ps1:164:1:177:1 | def of test-nested-try-outer-finally | try.ps1:179:1:194:1 | def of test-nested-try-inner-outer-finally |  |
+| try.ps1:164:40:177:1 | [synth] pipeline | try.ps1:165:5:176:12 | {...} |  |
 | try.ps1:164:40:177:1 | enter {...} | try.ps1:164:40:177:1 | {...} |  |
 | try.ps1:164:40:177:1 | exit {...} (normal) | try.ps1:164:40:177:1 | exit {...} |  |
-| try.ps1:164:40:177:1 | {...} | try.ps1:165:5:176:12 | {...} |  |
+| try.ps1:164:40:177:1 | {...} | try.ps1:164:40:177:1 | [synth] pipeline |  |
 | try.ps1:165:5:175:5 | try {...} | try.ps1:165:9:171:5 | {...} |  |
 | try.ps1:165:5:176:12 | {...} | try.ps1:165:5:175:5 | try {...} |  |
 | try.ps1:165:9:171:5 | {...} | try.ps1:166:9:170:9 | try {...} |  |
@@ -735,9 +744,10 @@
 | try.ps1:176:5:176:12 | return ... | try.ps1:176:12:176:12 | 1 |  |
 | try.ps1:176:12:176:12 | 1 | try.ps1:164:40:177:1 | exit {...} (normal) |  |
 | try.ps1:179:1:194:1 | def of test-nested-try-inner-outer-finally | try.ps1:1:1:194:1 | exit {...} (normal) |  |
+| try.ps1:179:46:194:1 | [synth] pipeline | try.ps1:180:5:193:12 | {...} |  |
 | try.ps1:179:46:194:1 | enter {...} | try.ps1:179:46:194:1 | {...} |  |
 | try.ps1:179:46:194:1 | exit {...} (normal) | try.ps1:179:46:194:1 | exit {...} |  |
-| try.ps1:179:46:194:1 | {...} | try.ps1:180:5:193:12 | {...} |  |
+| try.ps1:179:46:194:1 | {...} | try.ps1:179:46:194:1 | [synth] pipeline |  |
 | try.ps1:180:5:192:5 | try {...} | try.ps1:180:9:188:5 | {...} |  |
 | try.ps1:180:5:193:12 | {...} | try.ps1:180:5:192:5 | try {...} |  |
 | try.ps1:180:9:188:5 | {...} | try.ps1:181:9:187:9 | try {...} |  |
diff --git a/powershell/ql/test/library-tests/controlflow/graph/consistency.expected b/powershell/ql/test/library-tests/controlflow/graph/consistency.expected
index 33994ab4888b..6f6c4e8dca39 100644
--- a/powershell/ql/test/library-tests/controlflow/graph/consistency.expected
+++ b/powershell/ql/test/library-tests/controlflow/graph/consistency.expected
@@ -4,10 +4,6 @@ breakInvariant3
 breakInvariant4
 breakInvariant5
 multipleSuccessors
-| functions.ps1:8:5:8:23 | [Stmt] ...+... | successor | functions.ps1:8:5:8:12 | number1 |
-| functions.ps1:8:5:8:23 | [Stmt] ...+... | successor | functions.ps1:46:17:46:18 | __pipeline_iterator |
-| functions.ps1:8:5:8:23 | [Stmt] __pipeline_iterator | successor | functions.ps1:8:5:8:12 | number1 |
-| functions.ps1:8:5:8:23 | [Stmt] __pipeline_iterator | successor | functions.ps1:46:17:46:18 | __pipeline_iterator |
 | functions.ps1:13:28:20:1 | name1 | successor | functions.ps1:13:28:20:1 | name2 |
 | functions.ps1:13:28:20:1 | name1 | successor | functions.ps1:16:24:16:24 | 0 |
 | functions.ps1:13:28:20:1 | name2 | successor | functions.ps1:13:28:20:1 | [synth] pipeline |
@@ -16,20 +12,8 @@ multipleSuccessors
 | functions.ps1:16:24:16:24 | 0 | successor | functions.ps1:17:24:17:29 | name1 |
 | functions.ps1:17:24:17:33 | ...+... | successor | functions.ps1:13:28:20:1 | [synth] pipeline |
 | functions.ps1:17:24:17:33 | ...+... | successor | functions.ps1:13:28:20:1 | name0 |
-| functions.ps1:19:5:19:18 | [Stmt] ...+... | successor | functions.ps1:19:13:19:18 | name2 |
-| functions.ps1:19:5:19:18 | [Stmt] ...+... | successor | functions.ps1:46:17:46:18 | __pipeline_iterator |
-| functions.ps1:19:5:19:18 | [Stmt] __pipeline_iterator | successor | functions.ps1:19:13:19:18 | name2 |
-| functions.ps1:19:5:19:18 | [Stmt] __pipeline_iterator | successor | functions.ps1:46:17:46:18 | __pipeline_iterator |
-| functions.ps1:33:5:33:8 | [Stmt] __pipeline_iterator | successor | functions.ps1:33:5:33:8 | sum |
-| functions.ps1:33:5:33:8 | [Stmt] __pipeline_iterator | successor | functions.ps1:46:17:46:18 | __pipeline_iterator |
-| functions.ps1:33:5:33:8 | [Stmt] sum | successor | functions.ps1:33:5:33:8 | sum |
-| functions.ps1:33:5:33:8 | [Stmt] sum | successor | functions.ps1:46:17:46:18 | __pipeline_iterator |
-| functions.ps1:46:9:46:12 | sum | successor | functions.ps1:44:5:47:5 | {...} |
-| functions.ps1:46:9:46:12 | sum | successor | functions.ps1:48:5:51:5 | {...} |
-| functions.ps1:50:9:50:12 | [Stmt] __pipeline_iterator | successor | functions.ps1:46:17:46:18 | __pipeline_iterator |
-| functions.ps1:50:9:50:12 | [Stmt] __pipeline_iterator | successor | functions.ps1:50:9:50:12 | sum |
-| functions.ps1:50:9:50:12 | [Stmt] sum | successor | functions.ps1:46:17:46:18 | __pipeline_iterator |
-| functions.ps1:50:9:50:12 | [Stmt] sum | successor | functions.ps1:50:9:50:12 | sum |
+| functions.ps1:46:17:46:18 | __pipeline_iterator | successor | functions.ps1:44:5:47:5 | [synth] pipeline |
+| functions.ps1:46:17:46:18 | __pipeline_iterator | successor | functions.ps1:48:5:51:5 | {...} |
 | loops.ps1:45:14:45:19 | ...+... | successor | loops.ps1:44:18:44:19 | i |
 | loops.ps1:45:14:45:19 | ...+... | successor | loops.ps1:44:29:44:39 | ...=... |
 simpleAndNormalSuccessors
@@ -37,12 +21,4 @@ deadEnd
 nonUniqueSplitKind
 nonUniqueListOrder
 multipleToString
-| functions.ps1:8:5:8:23 | [Stmt] ...+... | [Stmt] ...+...,[Stmt] __pipeline_iterator |
-| functions.ps1:8:5:8:23 | [Stmt] __pipeline_iterator | [Stmt] ...+...,[Stmt] __pipeline_iterator |
-| functions.ps1:19:5:19:18 | [Stmt] ...+... | [Stmt] ...+...,[Stmt] __pipeline_iterator |
-| functions.ps1:19:5:19:18 | [Stmt] __pipeline_iterator | [Stmt] ...+...,[Stmt] __pipeline_iterator |
-| functions.ps1:33:5:33:8 | [Stmt] __pipeline_iterator | [Stmt] __pipeline_iterator,[Stmt] sum |
-| functions.ps1:33:5:33:8 | [Stmt] sum | [Stmt] __pipeline_iterator,[Stmt] sum |
-| functions.ps1:50:9:50:12 | [Stmt] __pipeline_iterator | [Stmt] __pipeline_iterator,[Stmt] sum |
-| functions.ps1:50:9:50:12 | [Stmt] sum | [Stmt] __pipeline_iterator,[Stmt] sum |
 scopeNoFirst
diff --git a/powershell/ql/test/library-tests/dataflow/local/flow.expected b/powershell/ql/test/library-tests/dataflow/local/flow.expected
index e7aa288529cb..c436626f9186 100644
--- a/powershell/ql/test/library-tests/dataflow/local/flow.expected
+++ b/powershell/ql/test/library-tests/dataflow/local/flow.expected
@@ -1,9 +1,9 @@
 | test.ps1:1:1:1:3 | a1 | test.ps1:2:6:2:8 | a1 |
-| test.ps1:1:1:21:27 | implicit unwrapping of {...} | test.ps1:1:1:21:27 | return value for {...} |
-| test.ps1:1:1:21:27 | pre-return value for {...} | test.ps1:1:1:21:27 | implicit unwrapping of {...} |
+| test.ps1:1:1:24:22 | implicit unwrapping of {...} | test.ps1:1:1:24:22 | return value for {...} |
+| test.ps1:1:1:24:22 | pre-return value for {...} | test.ps1:1:1:24:22 | implicit unwrapping of {...} |
 | test.ps1:1:7:1:12 | Call to Source | test.ps1:1:1:1:3 | a1 |
-| test.ps1:2:1:2:8 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
-| test.ps1:2:1:2:8 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
+| test.ps1:2:1:2:8 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
+| test.ps1:2:1:2:8 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
 | test.ps1:4:1:4:2 | b | test.ps1:5:4:5:5 | b |
 | test.ps1:4:6:4:12 | Call to GetBool | test.ps1:4:1:4:2 | b |
 | test.ps1:5:1:7:1 | phi | test.ps1:8:6:8:8 | a2 |
@@ -11,27 +11,31 @@
 | test.ps1:6:5:6:7 | a2 | test.ps1:6:11:6:16 | [input] phi |
 | test.ps1:6:11:6:16 | Call to Source | test.ps1:6:5:6:7 | a2 |
 | test.ps1:6:11:6:16 | [input] phi | test.ps1:5:1:7:1 | phi |
-| test.ps1:8:1:8:8 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
-| test.ps1:8:1:8:8 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
+| test.ps1:8:1:8:8 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
+| test.ps1:8:1:8:8 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
 | test.ps1:10:1:10:2 | c | test.ps1:11:6:11:7 | c |
 | test.ps1:10:6:10:15 | [...]... | test.ps1:10:1:10:2 | c |
 | test.ps1:10:14:10:15 | b | test.ps1:10:6:10:15 | [...]... |
-| test.ps1:11:1:11:7 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
-| test.ps1:11:1:11:7 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
+| test.ps1:11:1:11:7 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
+| test.ps1:11:1:11:7 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
 | test.ps1:11:6:11:7 | [post] c | test.ps1:13:7:13:8 | c |
 | test.ps1:11:6:11:7 | c | test.ps1:13:7:13:8 | c |
 | test.ps1:13:1:13:2 | d | test.ps1:14:6:14:7 | d |
 | test.ps1:13:6:13:9 | (...) | test.ps1:13:1:13:2 | d |
 | test.ps1:13:7:13:8 | c | test.ps1:13:6:13:9 | (...) |
-| test.ps1:14:1:14:7 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
-| test.ps1:14:1:14:7 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
+| test.ps1:14:1:14:7 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
+| test.ps1:14:1:14:7 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
 | test.ps1:14:6:14:7 | [post] d | test.ps1:16:6:16:7 | d |
 | test.ps1:14:6:14:7 | d | test.ps1:16:6:16:7 | d |
 | test.ps1:16:1:16:2 | e | test.ps1:17:6:17:7 | e |
 | test.ps1:16:6:16:11 | ...+... | test.ps1:16:1:16:2 | e |
-| test.ps1:17:1:17:7 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
-| test.ps1:17:1:17:7 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
+| test.ps1:17:1:17:7 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
+| test.ps1:17:1:17:7 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
 | test.ps1:19:1:19:2 | f | test.ps1:21:25:21:26 | f |
 | test.ps1:19:6:19:11 | Call to Source | test.ps1:19:1:19:2 | f |
-| test.ps1:21:1:21:27 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
-| test.ps1:21:1:21:27 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
+| test.ps1:21:1:21:27 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
+| test.ps1:21:1:21:27 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
+| test.ps1:23:1:23:6 | input | test.ps1:24:17:24:22 | input |
+| test.ps1:23:10:23:32 | Call to Read-Host | test.ps1:23:1:23:6 | input |
+| test.ps1:24:1:24:22 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
+| test.ps1:24:1:24:22 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
diff --git a/powershell/ql/test/library-tests/dataflow/local/taint.expected b/powershell/ql/test/library-tests/dataflow/local/taint.expected
index 381f685afbdf..7e6eeb95740a 100644
--- a/powershell/ql/test/library-tests/dataflow/local/taint.expected
+++ b/powershell/ql/test/library-tests/dataflow/local/taint.expected
@@ -1,10 +1,10 @@
 | test.ps1:1:1:1:3 | a1 | test.ps1:2:6:2:8 | a1 |
-| test.ps1:1:1:21:27 | implicit unwrapping of {...} | test.ps1:1:1:21:27 | return value for {...} |
-| test.ps1:1:1:21:27 | pre-return value for {...} | test.ps1:1:1:21:27 | implicit unwrapping of {...} |
-| test.ps1:1:1:21:27 | pre-return value for {...} | test.ps1:1:1:21:27 | implicit unwrapping of {...} |
+| test.ps1:1:1:24:22 | implicit unwrapping of {...} | test.ps1:1:1:24:22 | return value for {...} |
+| test.ps1:1:1:24:22 | pre-return value for {...} | test.ps1:1:1:24:22 | implicit unwrapping of {...} |
+| test.ps1:1:1:24:22 | pre-return value for {...} | test.ps1:1:1:24:22 | implicit unwrapping of {...} |
 | test.ps1:1:7:1:12 | Call to Source | test.ps1:1:1:1:3 | a1 |
-| test.ps1:2:1:2:8 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
-| test.ps1:2:1:2:8 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
+| test.ps1:2:1:2:8 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
+| test.ps1:2:1:2:8 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
 | test.ps1:4:1:4:2 | b | test.ps1:5:4:5:5 | b |
 | test.ps1:4:6:4:12 | Call to GetBool | test.ps1:4:1:4:2 | b |
 | test.ps1:5:1:7:1 | phi | test.ps1:8:6:8:8 | a2 |
@@ -12,30 +12,34 @@
 | test.ps1:6:5:6:7 | a2 | test.ps1:6:11:6:16 | [input] phi |
 | test.ps1:6:11:6:16 | Call to Source | test.ps1:6:5:6:7 | a2 |
 | test.ps1:6:11:6:16 | [input] phi | test.ps1:5:1:7:1 | phi |
-| test.ps1:8:1:8:8 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
-| test.ps1:8:1:8:8 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
+| test.ps1:8:1:8:8 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
+| test.ps1:8:1:8:8 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
 | test.ps1:10:1:10:2 | c | test.ps1:11:6:11:7 | c |
 | test.ps1:10:6:10:15 | [...]... | test.ps1:10:1:10:2 | c |
 | test.ps1:10:14:10:15 | b | test.ps1:10:6:10:15 | [...]... |
-| test.ps1:11:1:11:7 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
-| test.ps1:11:1:11:7 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
+| test.ps1:11:1:11:7 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
+| test.ps1:11:1:11:7 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
 | test.ps1:11:6:11:7 | [post] c | test.ps1:13:7:13:8 | c |
 | test.ps1:11:6:11:7 | c | test.ps1:13:7:13:8 | c |
 | test.ps1:13:1:13:2 | d | test.ps1:14:6:14:7 | d |
 | test.ps1:13:6:13:9 | (...) | test.ps1:13:1:13:2 | d |
 | test.ps1:13:7:13:8 | c | test.ps1:13:6:13:9 | (...) |
-| test.ps1:14:1:14:7 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
-| test.ps1:14:1:14:7 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
+| test.ps1:14:1:14:7 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
+| test.ps1:14:1:14:7 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
 | test.ps1:14:6:14:7 | [post] d | test.ps1:16:6:16:7 | d |
 | test.ps1:14:6:14:7 | d | test.ps1:16:6:16:7 | d |
 | test.ps1:16:1:16:2 | e | test.ps1:17:6:17:7 | e |
 | test.ps1:16:6:16:7 | d | test.ps1:16:6:16:11 | ...+... |
 | test.ps1:16:6:16:11 | ...+... | test.ps1:16:1:16:2 | e |
 | test.ps1:16:11:16:11 | 1 | test.ps1:16:6:16:11 | ...+... |
-| test.ps1:17:1:17:7 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
-| test.ps1:17:1:17:7 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
+| test.ps1:17:1:17:7 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
+| test.ps1:17:1:17:7 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
 | test.ps1:19:1:19:2 | f | test.ps1:21:25:21:26 | f |
 | test.ps1:19:6:19:11 | Call to Source | test.ps1:19:1:19:2 | f |
-| test.ps1:21:1:21:27 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
-| test.ps1:21:1:21:27 | Call to Sink | test.ps1:1:1:21:27 | pre-return value for {...} |
+| test.ps1:21:1:21:27 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
+| test.ps1:21:1:21:27 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
 | test.ps1:21:25:21:26 | f | test.ps1:21:6:21:27 | here is a string: $f |
+| test.ps1:23:1:23:6 | input | test.ps1:24:17:24:22 | input |
+| test.ps1:23:10:23:32 | Call to Read-Host | test.ps1:23:1:23:6 | input |
+| test.ps1:24:1:24:22 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
+| test.ps1:24:1:24:22 | Call to Sink | test.ps1:1:1:24:22 | pre-return value for {...} |
diff --git a/powershell/ql/test/library-tests/dataflow/local/test.ps1 b/powershell/ql/test/library-tests/dataflow/local/test.ps1
index 4e18ffb1f11a..ae64ad05b4fb 100644
--- a/powershell/ql/test/library-tests/dataflow/local/test.ps1
+++ b/powershell/ql/test/library-tests/dataflow/local/test.ps1
@@ -18,4 +18,7 @@ Sink $e
 
 $f = Source
 
-Sink "here is a string: $f"
\ No newline at end of file
+Sink "here is a string: $f"
+
+$input = Read-Host "enter input"
+Sink -UserInput $input
\ No newline at end of file
diff --git a/powershell/ql/test/library-tests/dataflow/pipeline/test.expected b/powershell/ql/test/library-tests/dataflow/pipeline/test.expected
index bbea92282028..5e3b383e7cc9 100644
--- a/powershell/ql/test/library-tests/dataflow/pipeline/test.expected
+++ b/powershell/ql/test/library-tests/dataflow/pipeline/test.expected
@@ -1,17 +1,87 @@
 models
 edges
+| test.ps1:2:10:2:19 | Call to Source | test.ps1:5:5:5:6 | x | provenance |  |
+| test.ps1:3:10:3:19 | Call to Source | test.ps1:6:5:6:6 | y | provenance |  |
+| test.ps1:4:10:4:19 | Call to Source | test.ps1:6:9:6:10 | z | provenance |  |
+| test.ps1:5:5:5:6 | x | test.ps1:17:1:17:7 | Call to produce [element] | provenance |  |
+| test.ps1:6:5:6:6 | y | test.ps1:17:1:17:7 | Call to produce [element] | provenance |  |
+| test.ps1:6:9:6:10 | z | test.ps1:17:1:17:7 | Call to produce [element] | provenance |  |
+| test.ps1:9:29:15:1 | [synth] pipeline [element 0] | test.ps1:12:5:14:5 | [synth] pipeline [element 0] | provenance |  |
+| test.ps1:9:29:15:1 | [synth] pipeline [element 1] | test.ps1:12:5:14:5 | [synth] pipeline [element 1] | provenance |  |
+| test.ps1:9:29:15:1 | [synth] pipeline [element] | test.ps1:12:5:14:5 | [synth] pipeline [element] | provenance |  |
+| test.ps1:12:5:14:5 | [synth] pipeline [element 0] | test.ps1:13:9:13:15 | __pipeline_iterator | provenance |  |
+| test.ps1:12:5:14:5 | [synth] pipeline [element 1] | test.ps1:13:9:13:15 | __pipeline_iterator | provenance |  |
+| test.ps1:12:5:14:5 | [synth] pipeline [element] | test.ps1:13:9:13:15 | __pipeline_iterator | provenance |  |
+| test.ps1:17:1:17:7 | Call to produce [element] | test.ps1:9:29:15:1 | [synth] pipeline [element] | provenance |  |
+| test.ps1:17:1:17:7 | Call to produce [element] | test.ps1:17:1:17:7 | Call to produce [element] | provenance |  |
+| test.ps1:19:6:19:15 | Call to Source | test.ps1:21:1:21:2 | x | provenance |  |
+| test.ps1:20:6:20:15 | Call to Source | test.ps1:21:5:21:6 | y | provenance |  |
+| test.ps1:21:1:21:2 | x | test.ps1:21:1:21:6 | ...,... [element 0] | provenance |  |
+| test.ps1:21:1:21:6 | ...,... [element 0] | test.ps1:9:29:15:1 | [synth] pipeline [element 0] | provenance |  |
+| test.ps1:21:1:21:6 | ...,... [element 0] | test.ps1:21:1:21:6 | ...,... [element 0] | provenance |  |
+| test.ps1:21:1:21:6 | ...,... [element 1] | test.ps1:9:29:15:1 | [synth] pipeline [element 1] | provenance |  |
+| test.ps1:21:1:21:6 | ...,... [element 1] | test.ps1:21:1:21:6 | ...,... [element 1] | provenance |  |
+| test.ps1:21:5:21:6 | y | test.ps1:21:1:21:6 | ...,... [element 1] | provenance |  |
+| test.ps1:23:38:27:1 | [synth] pipeline [element 0] | test.ps1:24:5:26:5 | [synth] pipeline [element 0] | provenance |  |
+| test.ps1:23:38:27:1 | [synth] pipeline [element 1] | test.ps1:24:5:26:5 | [synth] pipeline [element 1] | provenance |  |
+| test.ps1:24:5:26:5 | [synth] pipeline [element 0] | test.ps1:25:9:25:15 | __pipeline_iterator | provenance |  |
+| test.ps1:24:5:26:5 | [synth] pipeline [element 1] | test.ps1:25:9:25:15 | __pipeline_iterator | provenance |  |
+| test.ps1:29:6:29:15 | Call to Source | test.ps1:31:1:31:2 | x | provenance |  |
+| test.ps1:30:6:30:15 | Call to Source | test.ps1:31:5:31:6 | y | provenance |  |
+| test.ps1:31:1:31:2 | x | test.ps1:31:1:31:6 | ...,... [element 0] | provenance |  |
+| test.ps1:31:1:31:6 | ...,... [element 0] | test.ps1:23:38:27:1 | [synth] pipeline [element 0] | provenance |  |
+| test.ps1:31:1:31:6 | ...,... [element 0] | test.ps1:31:1:31:6 | ...,... [element 0] | provenance |  |
+| test.ps1:31:1:31:6 | ...,... [element 1] | test.ps1:23:38:27:1 | [synth] pipeline [element 1] | provenance |  |
+| test.ps1:31:1:31:6 | ...,... [element 1] | test.ps1:31:1:31:6 | ...,... [element 1] | provenance |  |
+| test.ps1:31:5:31:6 | y | test.ps1:31:1:31:6 | ...,... [element 1] | provenance |  |
 nodes
+| test.ps1:2:10:2:19 | Call to Source | semmle.label | Call to Source |
+| test.ps1:3:10:3:19 | Call to Source | semmle.label | Call to Source |
+| test.ps1:4:10:4:19 | Call to Source | semmle.label | Call to Source |
+| test.ps1:5:5:5:6 | x | semmle.label | x |
+| test.ps1:6:5:6:6 | y | semmle.label | y |
+| test.ps1:6:9:6:10 | z | semmle.label | z |
+| test.ps1:9:29:15:1 | [synth] pipeline [element 0] | semmle.label | [synth] pipeline [element 0] |
+| test.ps1:9:29:15:1 | [synth] pipeline [element 1] | semmle.label | [synth] pipeline [element 1] |
+| test.ps1:9:29:15:1 | [synth] pipeline [element] | semmle.label | [synth] pipeline [element] |
+| test.ps1:12:5:14:5 | [synth] pipeline [element 0] | semmle.label | [synth] pipeline [element 0] |
+| test.ps1:12:5:14:5 | [synth] pipeline [element 1] | semmle.label | [synth] pipeline [element 1] |
+| test.ps1:12:5:14:5 | [synth] pipeline [element] | semmle.label | [synth] pipeline [element] |
+| test.ps1:13:9:13:15 | __pipeline_iterator | semmle.label | __pipeline_iterator |
+| test.ps1:17:1:17:7 | Call to produce [element] | semmle.label | Call to produce [element] |
+| test.ps1:17:1:17:7 | Call to produce [element] | semmle.label | Call to produce [element] |
+| test.ps1:19:6:19:15 | Call to Source | semmle.label | Call to Source |
+| test.ps1:20:6:20:15 | Call to Source | semmle.label | Call to Source |
+| test.ps1:21:1:21:2 | x | semmle.label | x |
+| test.ps1:21:1:21:6 | ...,... [element 0] | semmle.label | ...,... [element 0] |
+| test.ps1:21:1:21:6 | ...,... [element 0] | semmle.label | ...,... [element 0] |
+| test.ps1:21:1:21:6 | ...,... [element 1] | semmle.label | ...,... [element 1] |
+| test.ps1:21:1:21:6 | ...,... [element 1] | semmle.label | ...,... [element 1] |
+| test.ps1:21:5:21:6 | y | semmle.label | y |
+| test.ps1:23:38:27:1 | [synth] pipeline [element 0] | semmle.label | [synth] pipeline [element 0] |
+| test.ps1:23:38:27:1 | [synth] pipeline [element 1] | semmle.label | [synth] pipeline [element 1] |
+| test.ps1:24:5:26:5 | [synth] pipeline [element 0] | semmle.label | [synth] pipeline [element 0] |
+| test.ps1:24:5:26:5 | [synth] pipeline [element 1] | semmle.label | [synth] pipeline [element 1] |
+| test.ps1:25:9:25:15 | __pipeline_iterator | semmle.label | __pipeline_iterator |
+| test.ps1:29:6:29:15 | Call to Source | semmle.label | Call to Source |
+| test.ps1:30:6:30:15 | Call to Source | semmle.label | Call to Source |
+| test.ps1:31:1:31:2 | x | semmle.label | x |
+| test.ps1:31:1:31:6 | ...,... [element 0] | semmle.label | ...,... [element 0] |
+| test.ps1:31:1:31:6 | ...,... [element 0] | semmle.label | ...,... [element 0] |
+| test.ps1:31:1:31:6 | ...,... [element 1] | semmle.label | ...,... [element 1] |
+| test.ps1:31:1:31:6 | ...,... [element 1] | semmle.label | ...,... [element 1] |
+| test.ps1:31:5:31:6 | y | semmle.label | y |
 subpaths
 testFailures
-| test.ps1:13:17:13:94 | # $ hasValueFlow=1 hasValueFlow=2 hasValueFlow=3 hasValueFlow=4 hasValueFlow=5 | Missing result: hasValueFlow=1 |
-| test.ps1:13:17:13:94 | # $ hasValueFlow=1 hasValueFlow=2 hasValueFlow=3 hasValueFlow=4 hasValueFlow=5 | Missing result: hasValueFlow=2 |
-| test.ps1:13:17:13:94 | # $ hasValueFlow=1 hasValueFlow=2 hasValueFlow=3 hasValueFlow=4 hasValueFlow=5 | Missing result: hasValueFlow=3 |
-| test.ps1:13:17:13:94 | # $ hasValueFlow=1 hasValueFlow=2 hasValueFlow=3 hasValueFlow=4 hasValueFlow=5 | Missing result: hasValueFlow=4 |
-| test.ps1:13:17:13:94 | # $ hasValueFlow=1 hasValueFlow=2 hasValueFlow=3 hasValueFlow=4 hasValueFlow=5 | Missing result: hasValueFlow=5 |
-| test.ps1:25:17:25:49 | # $ hasValueFlow=6 hasValueFlow=7 | Missing result: hasValueFlow=6 |
-| test.ps1:25:17:25:49 | # $ hasValueFlow=6 hasValueFlow=7 | Missing result: hasValueFlow=7 |
 | test.ps1:36:13:36:30 | # $ hasValueFlow=8 | Missing result: hasValueFlow=8 |
 | test.ps1:46:17:46:66 | # $ hasValueFlow=9 hasValueFlow=10 hasValueFlow=11 | Missing result: hasValueFlow=9 |
 | test.ps1:46:17:46:66 | # $ hasValueFlow=9 hasValueFlow=10 hasValueFlow=11 | Missing result: hasValueFlow=10 |
 | test.ps1:46:17:46:66 | # $ hasValueFlow=9 hasValueFlow=10 hasValueFlow=11 | Missing result: hasValueFlow=11 |
 #select
+| test.ps1:13:9:13:15 | __pipeline_iterator | test.ps1:2:10:2:19 | Call to Source | test.ps1:13:9:13:15 | __pipeline_iterator | $@ | test.ps1:2:10:2:19 | Call to Source | Call to Source |
+| test.ps1:13:9:13:15 | __pipeline_iterator | test.ps1:3:10:3:19 | Call to Source | test.ps1:13:9:13:15 | __pipeline_iterator | $@ | test.ps1:3:10:3:19 | Call to Source | Call to Source |
+| test.ps1:13:9:13:15 | __pipeline_iterator | test.ps1:4:10:4:19 | Call to Source | test.ps1:13:9:13:15 | __pipeline_iterator | $@ | test.ps1:4:10:4:19 | Call to Source | Call to Source |
+| test.ps1:13:9:13:15 | __pipeline_iterator | test.ps1:19:6:19:15 | Call to Source | test.ps1:13:9:13:15 | __pipeline_iterator | $@ | test.ps1:19:6:19:15 | Call to Source | Call to Source |
+| test.ps1:13:9:13:15 | __pipeline_iterator | test.ps1:20:6:20:15 | Call to Source | test.ps1:13:9:13:15 | __pipeline_iterator | $@ | test.ps1:20:6:20:15 | Call to Source | Call to Source |
+| test.ps1:25:9:25:15 | __pipeline_iterator | test.ps1:29:6:29:15 | Call to Source | test.ps1:25:9:25:15 | __pipeline_iterator | $@ | test.ps1:29:6:29:15 | Call to Source | Call to Source |
+| test.ps1:25:9:25:15 | __pipeline_iterator | test.ps1:30:6:30:15 | Call to Source | test.ps1:25:9:25:15 | __pipeline_iterator | $@ | test.ps1:30:6:30:15 | Call to Source | Call to Source |
diff --git a/powershell/ql/test/library-tests/ssa/ssa.expected b/powershell/ql/test/library-tests/ssa/ssa.expected
index 1cfa0788bbc6..b7615522d8ed 100644
--- a/powershell/ql/test/library-tests/ssa/ssa.expected
+++ b/powershell/ql/test/library-tests/ssa/ssa.expected
@@ -1,6 +1,6 @@
 | explicit.ps1:5:5:5:6 | a | explicit.ps1:5:5:5:6 | a |
 | explicit.ps1:6:5:6:6 | b | explicit.ps1:6:5:6:6 | b |
-| parameters.ps1:1:45:3:1 | <uninitialized> n1 | parameters.ps1:1:45:3:1 | n1 |
-| parameters.ps1:1:45:3:1 | <uninitialized> n2 | parameters.ps1:1:45:3:1 | n2 |
-| parameters.ps1:5:22:11:1 | <uninitialized> a | parameters.ps1:5:22:11:1 | a |
-| parameters.ps1:5:22:11:1 | <uninitialized> b | parameters.ps1:5:22:11:1 | b |
+| parameters.ps1:1:45:3:1 | n1 | parameters.ps1:1:45:3:1 | n1 |
+| parameters.ps1:1:45:3:1 | n2 | parameters.ps1:1:45:3:1 | n2 |
+| parameters.ps1:5:22:11:1 | a | parameters.ps1:5:22:11:1 | a |
+| parameters.ps1:5:22:11:1 | b | parameters.ps1:5:22:11:1 | b |