Metamath Proof Explorer


Theorem 9p7e16

Description: 9 + 7 = 16. (Contributed by Mario Carneiro, 19-Apr-2015)

Ref Expression
Assertion 9p7e16
|- ( 9 + 7 ) = ; 1 6

Proof

Step Hyp Ref Expression
1 9nn0
 |-  9 e. NN0
2 6nn0
 |-  6 e. NN0
3 5nn0
 |-  5 e. NN0
4 df-7
 |-  7 = ( 6 + 1 )
5 df-6
 |-  6 = ( 5 + 1 )
6 9p6e15
 |-  ( 9 + 6 ) = ; 1 5
7 1 2 3 4 5 6 6p5lem
 |-  ( 9 + 7 ) = ; 1 6