Theorem 6p6e12

Description: 6 + 6 = 12. (Contributed by Mario Carneiro, 19-Apr-2015)

	Ref	Expression
Assertion	6p6e12	|- ( 6 + 6 ) = ; 1 2

Proof

Step	Hyp	Ref	Expression
1		6nn0	|- 6 e. NN0
2		5nn0	|- 5 e. NN0
3		1nn0	|- 1 e. NN0
4		df-6	|- 6 = ( 5 + 1 )
5		df-2	|- 2 = ( 1 + 1 )
6		6p5e11	|- ( 6 + 5 ) = ; 1 1
7	1 2 3 4 5 6	6p5lem	|- ( 6 + 6 ) = ; 1 2