Metamath Proof Explorer

Theorem 7p4e11

Description: 7 + 4 = 11. (Contributed by Mario Carneiro, 19-Apr-2015) (Revised by AV, 6-Sep-2021)

Ref Expression
Assertion 7p4e11 
|- ( 7 + 4 ) = ; 1 1

Proof

Step Hyp Ref Expression
1 7nn0 
 |-  7 e. NN0
2 3nn0 
 |-  3 e. NN0
3 0nn0 
 |-  0 e. NN0
4 df-4 
 |-  4 = ( 3 + 1 )
5 1e0p1 
 |-  1 = ( 0 + 1 )
6 7p3e10 
 |-  ( 7 + 3 ) = ; 1 0
7 1 2 3 4 5 6 6p5lem 
 |-  ( 7 + 4 ) = ; 1 1