feat: add linter for rfl simp theorems at restricted transparency#13317
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leodemoura merged 1 commit intomasterfrom Apr 8, 2026
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feat: add linter for rfl simp theorems at restricted transparency#13317leodemoura merged 1 commit intomasterfrom
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This PR adds an opt-in linter (`set_option simp.rfl.checkTransparency true`) that warns when a `rfl` simp theorem's LHS and RHS are not definitionally equal at `.instances` transparency. Such theorems are problematic because `dsimp` cannot apply them at the transparency level `simp` actually uses. The warning suggests two fixes: use `id rfl` as the proof (to strip the `rfl` status), or mark relevant constants as `[implicit_reducible]`. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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This PR amends #13317 to suggest `:= (rfl)` as the recommended way to avoid a theorem to be automatically marked `[defeq]`, for consistency with existing documentation. Rationale: the special treatment of `:= rfl` is based on syntax, not the proof term, so it’s appropriate to use different syntax. And also I like the way it reads like a “muted whisper of `rfl`”.
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…anprover#13317) This PR adds an opt-in linter (`set_option simp.rfl.checkTransparency true`) that warns when a `rfl` simp theorem's LHS and RHS are not definitionally equal at `.instances` transparency. Bad rfl-simp theorems — those that only hold at higher transparency — create problems throughout the system because `simp` and `dsimp` operate at restricted transparency. The linter suggests two fixes: use `id rfl` as the proof (to remove the `rfl` status), or mark relevant constants as `[implicit_reducible]`. This is part of a broader effort to ensure `isDefEq` respects transparency levels. The linter helps systematically identify problematic rfl-simp theorems so they can be fixed incrementally. Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
wkrozowski
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Apr 10, 2026
This PR amends leanprover#13317 to suggest `:= (rfl)` as the recommended way to avoid a theorem to be automatically marked `[defeq]`, for consistency with existing documentation. Rationale: the special treatment of `:= rfl` is based on syntax, not the proof term, so it’s appropriate to use different syntax. And also I like the way it reads like a “muted whisper of `rfl`”.
wkrozowski
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Apr 12, 2026
This PR amends leanprover#13317 to suggest `:= (rfl)` as the recommended way to avoid a theorem to be automatically marked `[defeq]`, for consistency with existing documentation. Rationale: the special treatment of `:= rfl` is based on syntax, not the proof term, so it’s appropriate to use different syntax. And also I like the way it reads like a “muted whisper of `rfl`”.
volodeyka
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Apr 16, 2026
…3317) This PR adds an opt-in linter (`set_option simp.rfl.checkTransparency true`) that warns when a `rfl` simp theorem's LHS and RHS are not definitionally equal at `.instances` transparency. Bad rfl-simp theorems — those that only hold at higher transparency — create problems throughout the system because `simp` and `dsimp` operate at restricted transparency. The linter suggests two fixes: use `id rfl` as the proof (to remove the `rfl` status), or mark relevant constants as `[implicit_reducible]`. This is part of a broader effort to ensure `isDefEq` respects transparency levels. The linter helps systematically identify problematic rfl-simp theorems so they can be fixed incrementally. Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
volodeyka
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Apr 16, 2026
This PR amends #13317 to suggest `:= (rfl)` as the recommended way to avoid a theorem to be automatically marked `[defeq]`, for consistency with existing documentation. Rationale: the special treatment of `:= rfl` is based on syntax, not the proof term, so it’s appropriate to use different syntax. And also I like the way it reads like a “muted whisper of `rfl`”.
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This PR adds an opt-in linter (
set_option simp.rfl.checkTransparency true) that warns when arflsimp theorem's LHS and RHS are not definitionally equal at.instancestransparency. Bad rfl-simp theorems — those that only hold at higher transparency — create problems throughout the system becausesimpanddsimpoperate at restricted transparency. The linter suggests two fixes: useid rflas the proof (to remove therflstatus), or mark relevant constants as[implicit_reducible].This is part of a broader effort to ensure
isDefEqrespects transparency levels. The linter helps systematically identify problematic rfl-simp theorems so they can be fixed incrementally.