Metamath Proof Explorer


Theorem nnne0d

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

Ref Expression
Hypothesis nnge1d.1 φA
Assertion nnne0d φA0

Proof

Step Hyp Ref Expression
1 nnge1d.1 φA
2 nnne0 AA0
3 1 2 syl φA0