English
Let x,y commute in R with CharP R p. Then\n (x - y)^n = (x - y)^{n mod p} · (x^p - y^p)^{⌊n/p⌋}.
Русский
Пусть x,y коммутируют в R и CharP R p. Тогда\n (x - y)^n = (x - y)^{n mod p} · (x^p - y^p)^{⌊n/p⌋}.
LaTeX
$$$(x-y)^n = (x-y)^{n \\bmod p} \\cdot (x^p - y^p)^{\\left\\lfloor n/p \\right\\rfloor}$$$
Lean4
theorem neg_one_pow_expChar : (-1 : R) ^ p = -1 :=
by
rw [eq_neg_iff_add_eq_zero]
nth_rw 2 [← one_pow p]
rw [← add_pow_expChar_of_commute _ (Commute.one_right _), neg_add_cancel, zero_pow (expChar_ne_zero R p)]