English
Let R be a ring with CharP R p and t ∈ ℕ. If t is invertible in R and R is nontrivial, then ringChar R does not divide t.
Русский
Пусть R — кольцо с CharP R p и t ∈ ℕ. Если t обратим в R и R не тривиально, то ringChar R не делит t.
LaTeX
$${t : ℕ} [Invertible (t : R)] [Nontrivial R] : ringChar R ∤ t$$
Lean4
/-- When two is invertible in a ring, every element is `Odd`. -/
@[simp low]
theorem all [Ring R] [Invertible (2 : R)] (a : R) : Odd a :=
.of_isUnit_two (isUnit_of_invertible _) _