Add two new presolve techniques in combining probing and dual fixing

highs/lp_data/HighsOptions.h

@@ -477,6 +477,8 @@ struct HighsOptionsStruct {
   bool less_infeasible_DSE_check;
   bool less_infeasible_DSE_choose_row;
   bool use_original_HFactor_logic;
+  bool presolve_dfprobing;
+  bool presolve_gdf;
   //  bool allow_pdlp_cleanup;
   bool run_centring;
   HighsInt max_centring_steps;
@@ -1763,6 +1765,17 @@ class HighsOptions : public HighsOptionsStruct {
         advanced, &centring_ratio_tolerance, 0, 100, kHighsInf);
     records.push_back(record_double);
 
+    record_bool = new OptionRecordBool(
+        "presolve_dfprobing",
+        "Use the dual fixing aumgented probing technique in presolve", advanced,
+        &presolve_dfprobing, true);
+    records.push_back(record_bool);
+
+    record_bool = new OptionRecordBool(
+        "presolve_gdf", "Use the generalized dual fixing technique in presolve",
+        advanced, &presolve_gdf, true);
+    records.push_back(record_bool);
+
     // Set up the log_options aliases
     log_options.clear();
     log_options.log_stream =