Usw OrderBot / OrderTop for lattice witnesses

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Co-Authored-By: OpenAI Codex <codex@openai.com>
This commit is contained in:
2026-06-26 14:49:57 -05:00
parent 6a6ed521ca
commit e738eb4294
5 changed files with 51 additions and 30 deletions

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@@ -93,6 +93,14 @@ lemma bot_le' (a : AboveBelow α) : (bot : AboveBelow α) ≤ a :=
lemma le_top' (a : AboveBelow α) : a (top : AboveBelow α) :=
le_iff.mpr (sup_top a)
instance : OrderBot (AboveBelow α) where
bot := bot
bot_le := bot_le'
instance : OrderTop (AboveBelow α) where
top := top
le_top := le_top'
lemma bot_lt_mk (x : α) : (bot : AboveBelow α) < mk x :=
lt_of_le_of_ne (bot_le' _) (by simp)
@@ -224,6 +232,8 @@ lemma boundedChains : BoundedChains (AboveBelow α) 2 := fun c => by
instance [Inhabited α] : FiniteHeightLattice (AboveBelow α) where
toLattice := inferInstance
toOrderBot := inferInstance
toOrderTop := inferInstance
longestChain :=
((RelSeries.singleton _ bot).snoc (mk default)
(by rw [RelSeries.last_singleton]; exact bot_lt_mk default)).snoc top

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@@ -29,6 +29,8 @@ lemma boundedChains : BoundedChains Bool 1 := fun c => by
instance : FiniteHeightLattice Bool where
toLattice := inferInstance
toOrderBot := inferInstance
toOrderTop := inferInstance
longestChain := (RelSeries.singleton _ ( : Bool)).snoc ( : Bool)
(by rw [RelSeries.last_singleton]; exact bot_lt_top)
chains_bounded := boundedChains

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@@ -141,10 +141,12 @@ private def stdChain : (n : ) →
((FiniteHeightLattice.longestChain (α := β)).map
(fun b => (Fin.cons b ( : Fin n β) : Fin (n + 1) β)) consBot_strictMono)
(prev.1.map (fun f => (Fin.cons ( : β) f : Fin (n + 1) β)) consTop_strictMono)
(by rw [LTSeries.last_map, LTSeries.head_map, prev.2.1]; rfl),
(by
rw [LTSeries.last_map, LTSeries.head_map,
FiniteHeightLattice.longestChain_last, prev.2.1]),
by
simp only [RelSeries.head_smash, LTSeries.head_map]
rw [show (FiniteHeightLattice.longestChain (α := β)).head = ( : β) from rfl]
rw [FiniteHeightLattice.longestChain_head]
funext i
refine Fin.cases ?_ (fun j => ?_) i <;> simp [Pi.bot_apply],
by
@@ -154,6 +156,8 @@ private def stdChain : (n : ) →
instance instFiniteHeight {n : } : FiniteHeightLattice (Fin n β) where
toLattice := inferInstance
toOrderBot := inferInstance
toOrderTop := inferInstance
longestChain := (stdChain n).1
chains_bounded := fun c => by
obtain cs, _, _, hbound := exists_unzip c