English
If 1 < a in a commutative group with a partial order and IsOrderedMonoid, then a^m ≤ a^n iff m ≤ n.
Русский
Если a > 1, то a^m ≤ a^n эквивалентно m ≤ n.
LaTeX
$$$ [CommGroup \\alpha] [PartialOrder \\alpha] [IsOrderedMonoid \\alpha] {m n : \\mathbb{Z}} {a : \\alpha}, a > 1 \\Rightarrow (a^m ≤ a^n) \\iff (m ≤ n). $$$
Lean4
@[to_additive (attr := gcongr) zsmul_lt_zsmul_left]
theorem zpow_lt_zpow_right (ha : 1 < a) (h : m < n) : a ^ m < a ^ n :=
zpow_right_strictMono ha h