English
PerfectClosure(K, p) carries a p-th characteristic, i.e., CharP(PPerfectClosure(K, p), p) holds for the prime p and p-th characteristic in the base field lifts to the closure.
Русский
PerfectClosure(K, p) имеет характер p, то есть CharP(PerfectClosure(K, p), p) выполняется.
LaTeX
$$$\\text{CharP}(\\mathrm{PerfectClosure}\\,K\\,p, p)$$$
Lean4
instance instCharP : CharP (PerfectClosure K p) p := by
constructor; intro x; rw [← CharP.cast_eq_zero_iff K]
rw [← Nat.cast_zero, natCast_eq_iff, Nat.cast_zero]