7b496bf44b
This PR enhances the `cases` tactic used in the `grind` tactic and ensures that it can be applied to arbitrary expressions.
43 lines
1,022 B
Text
43 lines
1,022 B
Text
import Lean
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open Lean Meta Grind Elab Tactic in
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elab "cases' " e:term : tactic => withMainContext do
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let e ← elabTerm e none
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setGoals (← Grind.cases (← getMainGoal) e)
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inductive Vec (α : Type u) : Nat → Type u
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| nil : Vec α 0
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| cons : α → Vec α n → Vec α (n+1)
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def f (v : Vec α n) : Bool :=
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match v with
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| .nil => true
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| .cons .. => false
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/--
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info: n : Nat
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v : Vec Nat n
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h : f v ≠ false
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⊢ n + 1 = 0 → HEq (Vec.cons 10 v) Vec.nil → False
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---
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info: n : Nat
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v : Vec Nat n
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h : f v ≠ false
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⊢ ∀ {n_1 : Nat} (a : Nat) (a_1 : Vec Nat n_1), n + 1 = n_1 + 1 → HEq (Vec.cons 10 v) (Vec.cons a a_1) → False
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-/
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#guard_msgs (info) in
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example (v : Vec Nat n) (h : f v ≠ false) : False := by
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cases' (Vec.cons 10 v)
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next => trace_state; sorry
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next => trace_state; sorry
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/--
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info: ⊢ False → False
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---
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info: ⊢ True → False
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-/
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#guard_msgs (info) in
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example : False := by
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cases' (Or.inr (a := False) True.intro)
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next => trace_state; sorry
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next => trace_state; sorry
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