English
n.primeFactorsList = [] iff n = 0 or n = 1.
Русский
n.primeFactorsList = [] тогда и только тогда, когда n = 0 или n = 1.
LaTeX
$$$ n.primeFactorsList = [] \iff n = 0 \lor n = 1 $$$
Lean4
@[simp]
theorem primeFactorsList_eq_nil (n : ℕ) : n.primeFactorsList = [] ↔ n = 0 ∨ n = 1 :=
by
constructor <;> intro h
· rcases n with (_ | _ | n)
· exact Or.inl rfl
· exact Or.inr rfl
· rw [primeFactorsList] at h
injection h
· rcases h with (rfl | rfl)
· exact primeFactorsList_zero
· exact primeFactorsList_one