Metamath Proof Explorer


Theorem nnz

Description: A positive integer is an integer. (Contributed by NM, 9-May-2004) Reduce dependencies on axioms. (Revised by Steven Nguyen, 29-Nov-2022)

Ref Expression
Assertion nnz N N

Proof

Step Hyp Ref Expression
1 nnre N N
2 3mix2 N N = 0 N N
3 elz N N N = 0 N N
4 1 2 3 sylanbrc N N