6642061623
This PR makes `mvcgen with tac` fail if `tac` fails on one of the VCs, just as `induction ... with tac` fails if `tac` fails on one of the goals. The old behavior can be recovered by writing `mvcgen with try tac` instead.
41 lines
889 B
Text
41 lines
889 B
Text
import Std
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/-!
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`mvcgen with grind` should behave like `induction ... with grind` and fail if `grind` fails on
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one of the goals.
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-/
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open Std.Do
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set_option mvcgen.warning false
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set_option warn.sorry false
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variable {α : Type}
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@[grind]
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def List.last? (as : List α) : Option α :=
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match as with
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| [] => none
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| [a] => some a
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| _ :: bs => last? bs
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open List
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example (as bs : List α) (h : bs ≠ []) :
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(as ++ bs).last? = bs.last? := by
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fail_if_success induction bs generalizing as with simp
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sorry
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def nodup (l : List Int) : Bool := Id.run do
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let mut seen : Std.HashSet Int := ∅
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for x in l do
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if x ∈ seen then
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return false
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seen := seen.insert x
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return true
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theorem nodup_correct_invariants_with_pretac (l : List Int) : nodup l ↔ l.Nodup := by
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generalize h : nodup l = r
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apply Id.of_wp_run_eq h
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fail_if_success mvcgen with grind
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sorry
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