72bb7cf364
This PR fixes the dead `let` elimination code in the kernel's `infer_let` function. Closes #10475
29 lines
643 B
Text
29 lines
643 B
Text
import Lean
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open Lean
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/--
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info: let y : Type := Prop;
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let x : y := True;
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p x
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---
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info: let y : Type := Prop;
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let x : y := True;
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x
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---
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info: let y : Type := Prop;
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y
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-/
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#guard_msgs in
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set_option pp.letVarTypes true in
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example (p : ∀ a, a) :
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(let y := Prop; let x : y := True; p x) = p True := by
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run_tac
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let env ← Lean.getEnv
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let lctx ← getLCtx
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let_expr Eq _ lhs _ := (← Elab.Tactic.getMainTarget) | unreachable!
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logInfo lhs
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let ty ← ofExceptKernelException <| Lean.Kernel.check env lctx lhs
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logInfo ty
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let sort ← ofExceptKernelException <| Lean.Kernel.check env lctx ty
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logInfo sort
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trivial
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