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	$$⊢7+1=8$$