English
In a commutative monoid, (a b)^n = a^n b^n for all a,b and n.
Русский
В коммутативном моноиде для всех a,b и n верно (a b)^n = a^n b^n.
LaTeX
$$$(a b)^{n} = a^{n} b^{n}$$$
Lean4
@[to_additive nsmul_add]
theorem mul_pow (a b : M) : ∀ n, (a * b) ^ n = a ^ n * b ^ n
| 0 => by rw [pow_zero, pow_zero, pow_zero, one_mul]
| n + 1 => by rw [pow_succ', pow_succ', pow_succ', mul_pow, mul_mul_mul_comm]