3e2f1faebf
This PR introduces support for user-defined fallback code in the `grind` tactic. The fallback code can be utilized to inspect the state of failing `grind` subgoals and/or invoke user-defined automation. Users can now write `grind on_failure <code>`, where `<code>` should have the type `GoalM Unit`. See the modified tests in this PR for examples.
30 lines
936 B
Text
30 lines
936 B
Text
import Lean.Meta.Tactic.Grind
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def f (a : Nat) := a + a + a
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def g (a : Nat) := a + a
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def h (n : Nat) : Prop :=
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match n with
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| 0 => f 0 = f 1
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| n+1 => f (n+1) = f n ∧ g (2*n + 1) = g (2*n) ∧ h n
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-- Prints the equivalence class containing a `f` application
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open Lean Meta Grind in
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def fallback (n : Nat) : Fallback := do
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let f0 ← Grind.shareCommon (mkApp (mkConst ``f) (mkNatLit 0))
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-- The `f 0` equivalence class contains `n+1` elements
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assert! (← getEqc f0).length == n + 1
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forEachENode fun node => do
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if node.self.isAppOf ``g then
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-- Any equivalence class containing a `g`-application contains 2 elements
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assert! (← getEqc (← getRoot node.self)).length == 2
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(← get).mvarId.admit
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set_option grind.debug true in
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example : h 5 → False := by
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simp [h]
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grind on_failure fallback 5
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set_option maxRecDepth 2048
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example : h 100 → False := by
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simp [h]
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grind on_failure fallback 100
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