73751bbb27
This PR fixes a bug where `simp` made no progress on class projection reductions when `backward.whnf.reducibleClassField` is `true`. - In `reduceProjFn?`, for class projections applied to constructor instances (`Class.projFn (Class.mk ...)`), the code called `reduceProjCont? (← unfoldDefinitionAny? e)`. The helper `reduceProjCont?` expects the unfolded result to have a `.proj` head so it can apply `reduceProj?`. However, when `reducibleClassField` is enabled, `unfoldDefault` in WHNF.lean already reduces the `.proj` node during unfolding, so `reduceProjCont?` discards the fully-reduced result. - The fix uses `unfoldDefinitionAny?` directly, bypassing `reduceProjCont?`. The dsimp traversal revisits the result (via `.visit`) and handles any remaining `.proj` nodes naturally. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
9 lines
356 B
Text
9 lines
356 B
Text
set_option backward.whnf.reducibleClassField true in
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example [Ord α] {a b : α} :
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(letI : Ord α := ⟨fun a b => compare b a⟩; compare a b) = compare b a := by
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simp only
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set_option backward.whnf.reducibleClassField true in
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example [Ord α] {a b : α} :
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(letI : Ord α := ⟨fun a b => compare b a⟩; compare a b) = compare b a := by
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simp
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