Theorem 3p4e7

Description: 3 + 4 = 7. (Contributed by SN, 24-Aug-2026)

	Ref	Expression
Assertion	3p4e7	|- ( 3 + 4 ) = 7

Proof

Step	Hyp	Ref	Expression
1		3cn	|- 3 e. CC
2		2cn	|- 2 e. CC
3	1 2 2	addassi	|- ( ( 3 + 2 ) + 2 ) = ( 3 + ( 2 + 2 ) )
4		3p2e5	|- ( 3 + 2 ) = 5
5	4	oveq1i	|- ( ( 3 + 2 ) + 2 ) = ( 5 + 2 )
6		5p2e7	|- ( 5 + 2 ) = 7
7	5 6	eqtri	|- ( ( 3 + 2 ) + 2 ) = 7
8		2p2e4	|- ( 2 + 2 ) = 4
9	8	oveq2i	|- ( 3 + ( 2 + 2 ) ) = ( 3 + 4 )
10	3 7 9	3eqtr3ri	|- ( 3 + 4 ) = 7