Metamath Proof Explorer


Theorem peano2zd

Description: Deduction from second Peano postulate generalized to integers. (Contributed by Mario Carneiro, 28-May-2016)

Ref Expression
Hypothesis zred.1
|- ( ph -> A e. ZZ )
Assertion peano2zd
|- ( ph -> ( A + 1 ) e. ZZ )

Proof

Step Hyp Ref Expression
1 zred.1
 |-  ( ph -> A e. ZZ )
2 peano2z
 |-  ( A e. ZZ -> ( A + 1 ) e. ZZ )
3 1 2 syl
 |-  ( ph -> ( A + 1 ) e. ZZ )