lecopivo

Use when Lean files elaborate slowly, profiler output shows expensive typeclass/simp/grind/tactic work, automation annotations need tuning, or a proof/API design causes costly elaboration while source code should remain readable.

Use when designing Lean/mathlib APIs for isomorphic type wrappers, type synonyms, subtype-like injective forgetful maps, coercions, casts, simp/norm_cast normal forms, extensionality, or function-like bundled objects.