[Merged by Bors] - chore: standardise names for coercions from morphism classes to morphisms

[grunweg]

Following item (2) in #31365, the definition which implements the coercion from a morphism class FooHomClass to FooHoms should be called FooHom.ofClass.

• the name is easy to remember and guess
• it matches the existing names we have for the corresponding declarations for subobjects
• when Lean expects a FooHom, you can write .ofClass f.

Make five more morphism classes follow this pattern.

---

[github-actions]

PR summary 6947e22e01

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff (regex)

+ OrderIso.ofClass
+ StarAlgEquiv.ofClass
+ StarAlgEquivClass.instCoeHead
+ StarAlgEquivClass.toStarAlgEquiv
+ _root_.NonUnitalStarAlgHom.ofClass
+ _root_.NonUnitalStarRingHom.ofClass
+ _root_.OrderHom.ofClass
+ _root_.StarAlgHom.ofClass
+ _root_.StarRingEquiv.ofClass
+ instance : PreservesFiniteColimits (OrderHom.ofClass f).toFunctor
+ instance : PreservesFiniteLimits (OrderHom.ofClass f).toFunctor
- instCoeHead
- instance : PreservesFiniteColimits (toOrderHom f).toFunctor
- instance : PreservesFiniteLimits (toOrderHom f).toFunctor
- toStarAlgEquiv

You can run this locally as follows

## from your `mathlib4` directory:
git clone https://github.com/leanprover-community/mathlib-ci.git ../mathlib-ci

## summary with just the declaration names:
../mathlib-ci/scripts/pr_summary/declarations_diff.sh <optional_commit>

## more verbose report:
../mathlib-ci/scripts/pr_summary/declarations_diff.sh long <optional_commit>

The doc-module for scripts/pr_summary/declarations_diff.sh in the mathlib-ci repository contains some details about this script.

Declarations diff (Lean)

✅ Lean-aware diff — post-build, computed from the Lean environment (commit 6947e22).

• +15 new declarations
• −8 removed declarations

+CategoryTheory.Limits.CompleteLattice.instPreservesFiniteColimitsToFunctorOfClass
-CategoryTheory.Limits.CompleteLattice.instPreservesFiniteColimitsToFunctorToOrderHom
+CategoryTheory.Limits.CompleteLattice.instPreservesFiniteLimitsToFunctorOfClass
-CategoryTheory.Limits.CompleteLattice.instPreservesFiniteLimitsToFunctorToOrderHom
+NonUnitalStarAlgHom.ofClass
+NonUnitalStarAlgHom.ofClass.congr_simp
-NonUnitalStarAlgHomClass.toNonUnitalStarAlgHom.congr_simp
+NonUnitalStarRingHom.ofClass
+OrderHom.ofClass
+OrderHom.ofClass.congr_simp
-OrderHomClass.toOrderHom.congr_simp
+OrderIso.ofClass
+OrderIso.ofClass.congr_simp
-OrderIsoClass.toOrderIso.congr_simp
+StarAlgEquiv.ofClass
+StarAlgEquiv.ofClass.congr_simp
-StarAlgEquivClass.toStarAlgEquiv.congr_simp
+StarAlgHom.ofClass
+StarAlgHom.ofClass.congr_simp
-StarAlgHomClass.toStarAlgHom.congr_simp
+StarRingEquiv.ofClass
+StarRingEquiv.ofClass.congr_simp
-StarRingEquivClass.toStarRingEquiv.congr_simp

---

No changes to strong technical debt.
No changes to weak technical debt.

Current commit 6947e22e01
Reference commit a4d9f2fdd2

This script lives in the mathlib-ci repository. To run it locally, from your mathlib4 directory:

git clone https://github.com/leanprover-community/mathlib-ci.git ../mathlib-ci
../mathlib-ci/scripts/reporting/technical-debt-metrics.py pr_summary

• The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
• The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).

[mcdoll]

Thanks!
maintainer merge

[github-actions]

🚀 Pull request has been placed on the maintainer queue by mcdoll.

[mathlib-merge-conflicts]

This pull request has conflicts, please merge master and resolve them.

[eric-wieser]

bors d+

Looks great, thanks for splitting into a bitesize piece!

[mathlib-bors]

✌️ grunweg can now approve this pull request until 2026-09-21 07:03 UTC (in 2 weeks). To approve and merge, reply with bors r+. More detailed instructions are available here.

⚠️ This delegation only covers changes within Archive/**, Counterexamples/**, docs/**, DownstreamTest/**, Mathlib/**, MathlibTest/**, Wanted/**, widget/**, Archive.lean, Counterexamples.lean, docs.lean, Mathlib.lean, Wanted.lean; an author commit touching anything else will revoke it. Bors also revokes it if a later push changes too many files for it to check the full list — even if it stays within scope.

[mathlib-auto-merge]

As this PR is labelled auto-merge-after-CI, we are now sending it to bors:

bors merge

[mathlib-bors]

Build failed (retrying...):

• ci (staging) / Build

[mathlib-bors]

Pull request successfully merged into master.

Build succeeded:

• ci (staging) / Lint style
• ci (staging) / Build
• ci (staging) / Post-Build Step
• ci (staging) / Test and lint
• ci (staging) / Post-CI job