English
An isomorphism of ordered monoids descends to their units.
Русский
Изоморфизм упорядоченных моноидов порождает изоморфизм их единиц.
LaTeX
$$$ \text{unitsCongr}: \alpha^{\times} \simeq_o \beta^{\times} $$$
Lean4
/-- An isomorphism of ordered monoids descends to their units. -/
@[simps!]
def unitsCongr {α β : Type*} [Preorder α] [Monoid α] [Preorder β] [Monoid β] (e : α ≃*o β) : αˣ ≃*o βˣ
where
__ := Units.mapEquiv e.toMulEquiv
map_le_map_iff' {x y} := by simp [← Units.val_le_val]