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Remove maximal chain witness from FiniteHeightLattice

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Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
Danila Fedorin
2026-06-26 15:04:18 -05:00
parent e738eb4294
commit 5737805125
5 changed files with 13 additions and 87 deletions
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4
lean/Spa/Fixedpoint.lean
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@@ -12,7 +12,7 @@ def doStep (f : α → α) (hf : Monotone f) :
∀ (g : ℕ) (c : LTSeries α), c.length + g = height (α := α) + 1 →
c.last ≤ f c.last → {a : α // a = f a}
| 0, c, hlen, _ =>
absurd (FiniteHeightLattice.chains_bounded c) (by simp only [height] at hlen; omega)
absurd (FiniteHeightLattice.chains_bounded c) (by omega)
| g + 1, c, hlen, hle =>
if heq : c.last = f c.last then
⟨c.last, heq⟩
@@ -39,7 +39,7 @@ lemma doStep_le (f : α → α) (hf : Monotone f)
(hle : c.last ≤ f c.last), c.last ≤ b →
(doStep f hf g c hlen hle : α) ≤ b
| 0, c, hlen, _ => fun _ =>
absurd (FiniteHeightLattice.chains_bounded c) (by simp only [height] at hlen; omega)
absurd (FiniteHeightLattice.chains_bounded c) (by omega)
| g + 1, c, hlen, hle => fun hcb => by
rw [doStep]
split