English
For α with a PartialOrder, AddMonoidWithOne, ZeroLEOneClass and SuccAddOrder, for a in WithBot α, 1 ≤ a if and only if 0 < a.
Русский
Для α с частичным порядком, AddMonoidWithOne, ZeroLEOneClass и SuccAddOrder, для a ∈ WithBot α верно: 1 ≤ a тогда и только если 0 < a.
LaTeX
$$$$1 \le a \iff 0 < a,$$$$
Lean4
theorem one_le_iff_pos {α : Type*} [PartialOrder α] [AddMonoidWithOne α] [ZeroLEOneClass α] [NeZero (1 : α)]
[SuccAddOrder α] (a : WithBot α) : 1 ≤ a ↔ 0 < a := by cases a <;> simp [Order.one_le_iff_pos]