Metamath Proof Explorer


Theorem nnne0d

Description: A positive integer is nonzero. (Contributed by Mario Carneiro, 27-May-2016)

Ref Expression
Hypothesis nnge1d.1 φ A
Assertion nnne0d φ A 0

Proof

Step Hyp Ref Expression
1 nnge1d.1 φ A
2 nnne0 A A 0
3 1 2 syl φ A 0