Lean 4 fork for HoTT-compatible kernel extensions (Path types, transport, HITs). Maintained against upstream leanprover/lean4.
d1f0db7072
Note that test for issue #1200 broke. The bug fixed by this commit was allowing the example to be elaborated correctly :( Initially, the type of the discriminant is not available, and `.none (α:=α)` can only be elaborated when the expected type is of the form `C ...`. Lean then tries to elaborate the alternatives, learn that the discriminant should be `Option ?m`, and fails because the patterns still have metavariables after elaboration. Before the bug fix, `resumePostpone` was **not** restoring the metavariable context, and the assingnment would stay there. With this information, Lean can now elaborate `.none (α:=α)`. Although the bug had a positive impact in this case, it produced incorrect behavior in other examples. The fixed example looks reasonable. Thus, we will not reopen issue #1200 |
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This is the repository for Lean 4, which is currently being released as milestone releases towards a first stable release. Lean 3 is still the latest stable release.
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