fix: kernel error from simp results cached with a proof that has free variables - #14965
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…ee variables This PR fixes `simp` producing a proof with free variables, rejected by the kernel with "declaration has free variables", when the same `match` application occurs in two branches of a `dite`. This also affected the equation lemmas generated for well-founded definitions containing such a term. `simp` caches results by expression, so the proof of a cached result must not mention local hypotheses that `simp` introduced itself while descending into the term (see `Methods.wellBehavedDischarge`). `dischargeEqnThmHypothesis?` violated this: proving a match-equation side condition substitutes a discriminant, and `subst` reverts every hypothesis depending on it, pulling e.g. the `dite` hypothesis into the proof. It now clears those hypotheses from the goal first; `tryClearMany` keeps the ones the side condition itself depends on. Closes #14961. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Nk92q7cJwjqGyg8kep2Gyi
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Claude generated fix. Sounds plausible, but probably deserves a review of someone with better knowledge of the simp cache. Leaving it here as a draft for now. |
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This PR fixes
simpproducing a proof with free variables, rejected by the kernel with "declaration has free variables", when the samematchapplication occurs in two branches of adite. This also affected the equation lemmas generated for well-founded definitions containing such a term.simpcaches results by expression, so the proof of a cached result must not mention local hypotheses thatsimpintroduced itself while descending into the term (seeMethods.wellBehavedDischarge).dischargeEqnThmHypothesis?violated this: proving a match-equation side condition substitutes a discriminant, andsubstreverts every hypothesis depending on it, pulling e.g. theditehypothesis into the proof. It now clears those hypotheses from the goal first;tryClearManykeeps the ones the side condition itself depends on.Closes #14961.
Co-Authored-By: Claude Opus 5 (1M context) noreply@anthropic.com
Claude-Session: https://claude.ai/code/session_01Nk92q7cJwjqGyg8kep2Gyi