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

View File

@@ -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