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fix: remove obsolete sentence in doc-string (#6185)

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Even if this sentence is technically true, it do not add anything to the
explanation of typechecker and code.
This commit is contained in:
Andrii Kurdiumov
2024-11-23 13:56:31 +06:00
committed by GitHub
parent 107a2e8b2e
commit 51d1cc61d7
1 changed files with 1 additions and 3 deletions
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doc/examples/tc.lean
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@@ -82,9 +82,7 @@ theorem Expr.typeCheck_correct (h₁ : HasType e ty) (h₂ : e.typeCheck ≠ .un
/-!
Now, we prove that if `Expr.typeCheck e` returns `Maybe.unknown`, then forall `ty`, `HasType e ty` does not hold.
The notation `e.typeCheck` is sugar for `Expr.typeCheck e`. Lean can infer this because we explicitly said that `e` has type `Expr`.
The proof is by induction on `e` and case analysis. The tactic `rename_i` is used to rename "inaccessible" variables.
We say a variable is inaccessible if it is introduced by a tactic (e.g., `cases`) or has been shadowed by another variable introduced
by the user. Note that the tactic `simp [typeCheck]` is applied to all goal generated by the `induction` tactic, and closes
The proof is by induction on `e` and case analysis. Note that the tactic `simp [typeCheck]` is applied to all goal generated by the `induction` tactic, and closes
the cases corresponding to the constructors `Expr.nat` and `Expr.bool`.
-/
theorem Expr.typeCheck_complete {e : Expr} : e.typeCheck = .unknown → ¬ HasType e ty := by