Metamath Proof Explorer

Theorem 9pos

Description: The number 9 is positive. (Contributed by NM, 27-May-1999) (Proof shortened by Umit Teoman Dogan, 10-Jun-2026)

Ref Expression
Assertion 9pos 
|- 0 < 9

Proof

Step Hyp Ref Expression
1 9nn 
 |-  9 e. NN
2 1 nngt0i 
 |-  0 < 9