English
Under NoMinOrder, pred is strictly monotone: x < y implies pred x < pred y.
Русский
При условии NoMinOrder предшественник строго монотонен: x < y ⇒ pred x < pred y.
LaTeX
$$$$ [\mathrm{NoMinOrder}\;\alpha]\ (x,y):\mathrm{WithTop}\,\alpha,\ x < y \Rightarrow \operatorname{pred} x < \operatorname{pred} y $$$$
Lean4
theorem pred_strictMono [NoMinOrder α] : StrictMono (pred : WithTop α → α)
| (b : α), ⊤, hab => by simp
| (a : α), (b : α), hab => Order.pred_lt_pred (by simpa using hab)