feat: allow anonymous equality proofs in match expressions
#6853
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| theorem test_tactic (n : Nat) (h : n - 1 > 2) : n - 1 > 2 := by | ||
| match _ : n - 1 with |
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Would this work with ifs? Do they lower to match?
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To make sure I understand, are you asking whether Lean supports something like if _ : some_decidable_prop then ... else ...? If so, then yes, this was actually already supported; the purpose of this PR was to provide parity between match and if (see the example in #6759). Regarding whether if elaborates to a match: no, dependent if expressions elaborate to an application of dite, which is defined using the recursor for Decidable directly.
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This PR adds support for anonymous equality proofs in
matchexpressions of the formmatch _ : e with ....Closes #6759.