English
If f is antiperiodic with c, then for nonzero a the function x ↦ f(x • a) is antiperiodic with period c / a.
Русский
Если f антипериодична с периодом c, то для не нулевого a функция x ↦ f(x • a) антипериодична с периодом c / a.
LaTeX
$$$\text{Antiperiodic}(f(x\cdot a), c / a)$ for all $a \neq 0$$$
Lean4
theorem mul_const' [DivisionSemiring α] [Neg β] (h : Antiperiodic f c) {a : α} (ha : a ≠ 0) :
Antiperiodic (fun x => f (x * a)) (c / a) := by simpa only [div_eq_mul_inv] using h.mul_const ha