Metamath Proof Explorer


Theorem nnsgt0

Description: A positive integer is greater than zero. (Contributed by Scott Fenton, 15-Apr-2025)

Ref Expression
Assertion nnsgt0
|- ( A e. NN_s -> 0s 

Proof

Step Hyp Ref Expression
1 nnssn0s
 |-  NN_s C_ NN0_s
2 1 sseli
 |-  ( A e. NN_s -> A e. NN0_s )
3 n0sge0
 |-  ( A e. NN0_s -> 0s <_s A )
4 2 3 syl
 |-  ( A e. NN_s -> 0s <_s A )
5 nnne0s
 |-  ( A e. NN_s -> A =/= 0s )
6 0sno
 |-  0s e. No
7 6 a1i
 |-  ( A e. NN_s -> 0s e. No )
8 nnsno
 |-  ( A e. NN_s -> A e. No )
9 7 8 sltlend
 |-  ( A e. NN_s -> ( 0s  ( 0s <_s A /\ A =/= 0s ) ) )
10 4 5 9 mpbir2and
 |-  ( A e. NN_s -> 0s