English
A formal construction of the diamond isomorphism between Ioo intervals for modular lattices with IsModularLattice structure.
Русский
Формальная конструкция diamond-изоморфизма между интервалами Ioo для модульных решёток.
LaTeX
$$$\text{InfIooOrderIsoIooSup}(a,b)\text{ is an order isomorphism between } Ioo(a\wedge b,a) \text{ and } Ioo(b,a\vee b).$$$
Lean4
instance (priority := 100) to_isLowerModularLattice : IsLowerModularLattice α :=
⟨fun {a b} =>
by
simp_rw [covBy_iff_Ioo_eq, sup_comm a, inf_comm a, ← isEmpty_coe_sort, right_lt_sup, inf_lt_left,
(infIooOrderIsoIooSup b a).symm.toEquiv.isEmpty_congr]
exact id⟩
-- See note [lower instance priority]