Metamath Proof Explorer


Theorem nnn0

Description: The set of positive integers is nonempty. (Contributed by Glauco Siliprandi, 8-Apr-2021)

Ref Expression
Assertion nnn0 ⊢ ℕ ≠ ∅

Proof

Step Hyp Ref Expression
1 1nn ⊢ 1 ∈ ℕ
2 1 ne0ii ⊢ ℕ ≠ ∅