fix: handle multi-discriminant casesOn in WF unfold equation generation#13232
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This PR fixes a panic when compiling mutually recursive definitions that use `casesOn` on indexed inductive types (e.g. `Vect`). The `splitMatchOrCasesOn` function asserted `matcherInfo.numDiscrs = 1`, but for indexed types the casesOn has multiple discriminants (indices + major premise). The fix uses the last discriminant (the major premise) and lets the `cases` tactic handle index discriminants automatically. Closes #13015 Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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…on (#13232) This PR fixes a panic when compiling mutually recursive definitions that use `casesOn` on indexed inductive types (e.g. `Vect`). The `splitMatchOrCasesOn` function in `WF.Unfold` asserted `matcherInfo.numDiscrs = 1`, but for indexed types the casesOn recursor has multiple discriminants (indices + major premise). The fix uses the last discriminant (the major premise) and lets the `cases` tactic handle index discriminants automatically. Closes #13015 Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com> Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
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This PR fixes a panic when compiling mutually recursive definitions that use
casesOnon indexed inductive types (e.g.Vect). ThesplitMatchOrCasesOnfunction inWF.UnfoldassertedmatcherInfo.numDiscrs = 1, but for indexed types the casesOn recursor has multiple discriminants (indices + major premise). The fix uses the last discriminant (the major premise) and lets thecasestactic handle index discriminants automatically.Closes #13015
Co-Authored-By: Claude Opus 4.6 noreply@anthropic.com