Metamath Proof Explorer


Theorem 7p1e8

Description: 7 + 1 = 8. (Contributed by Mario Carneiro, 18-Apr-2015)

Ref Expression
Assertion 7p1e8
|- ( 7 + 1 ) = 8

Proof

Step Hyp Ref Expression
1 df-8
 |-  8 = ( 7 + 1 )
2 1 eqcomi
 |-  ( 7 + 1 ) = 8