1c1c534a03
This PR adds `solve_by_elim` as a fallback in the `try?` tactic's simple
tactics. When `rfl` and `assumption` both fail but `solve_by_elim`
succeeds (e.g., for goals requiring hypothesis chaining or
backtracking), `try?` will now suggest `solve_by_elim`.
The structure is `first | (attempt_all | rfl | assumption) |
solve_by_elim`, so `solve_by_elim` only runs when the faster tactics
fail.
This is a prerequisite for removing the "first pass" `solve_by_elim`
from `apply?`. Currently `apply?` calls `solve_by_elim` twice: once
before library search, and once after each lemma application. The first
pass can be removed once `try?` includes `solve_by_elim`.
🤖 Prepared with Claude Code
---------
Co-authored-by: Claude <noreply@anthropic.com>
31 lines
1.1 KiB
Text
31 lines
1.1 KiB
Text
/-
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Tests for try? integration with solve_by_elim.
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This tests that `try?` now includes `solve_by_elim` in its pipeline,
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which is a prerequisite for removing the "first pass" solve_by_elim from `apply?`.
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-/
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set_option autoImplicit true
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-- Basic hypothesis chaining: solve_by_elim can chain f and g to get from a to γ
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-- This requires more than just `assumption` - it needs to apply f then g
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example {α β γ : Type} (f : α → β) (g : β → γ) (a : α) : γ := by
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try?
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-- Multi-step application: needs to apply f four times
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example {α : Nat → Type} (f : (n : Nat) → α n → α (n+1)) (a : α 0) : α 4 := by
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try?
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-- Backtracking case: needs to find the right combination of hypotheses
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example (P₁ P₂ : α → Prop) (f : ∀ (a: α), P₁ a → P₂ a → β)
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(a : α) (_ha₁ : P₁ a)
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(a' : α) (ha'₁ : P₁ a') (ha'₂ : P₂ a') : β := by
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try?
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-- Simple case that could be solved by either assumption or solve_by_elim
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example (h : Nat) : Nat := by
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try?
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-- Two-argument function application
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example {α β : Type} (f : α → α → β) (a : α) : β := by
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try?
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