English
The OrderTop structure on α is a Subsingleton; any two such structures coincide.
Русский
Структура OrderTop на α является Subsingleton; любые две такие структуры совпадают.
LaTeX
$$$\forall \alpha, Subsingleton (OrderTop \alpha)$$$
Lean4
theorem ext_bot {α} {hA : PartialOrder α} (A : OrderBot α) {hB : PartialOrder α} (B : OrderBot α)
(H :
∀ x y : α,
(haveI := hA;
x ≤ y) ↔
x ≤ y) :
(@Bot.bot α (@OrderBot.toBot α hA.toLE A)) = (@Bot.bot α (@OrderBot.toBot α hB.toLE B)) :=
by
cases PartialOrder.ext H
apply bot_unique
exact @bot_le _ _ A _