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Metamath Proof Explorer

Theorem 7p7e14

Description: 7 + 7 = 14. (Contributed by Mario Carneiro, 19-Apr-2015)

		Ref	Expression
	Assertion	7p7e14	$⊢ 7 + 7 = 14$

Step	Hyp	Ref	Expression
1		7nn0	$⊢ 7 \in ℕ_{0}$
2		6nn0	$⊢ 6 \in ℕ_{0}$
3		3nn0	$⊢ 3 \in ℕ_{0}$
4		df-7	$⊢ 7 = 6 + 1$
5		df-4	$⊢ 4 = 3 + 1$
6		7p6e13	$⊢ 7 + 6 = 13$
7	1 2 3 4 5 6	6p5lem	$⊢ 7 + 7 = 14$