Theorem 4t4e16

Description: 4 times 4 equals 16. (Contributed by Mario Carneiro, 19-Apr-2015)

	Ref	Expression
Assertion	4t4e16	$$⊢4\cdot 4=16$$

Proof

Step	Hyp	Ref	Expression
1		4nn0	$$⊢4\in {\mathbb{N}}_0$$
2		3nn0	$$⊢3\in {\mathbb{N}}_0$$
3		df-4	$$⊢4=3+1$$
4		4t3e12	$$⊢4\cdot 3=12$$
5		1nn0	$$⊢1\in {\mathbb{N}}_0$$
6		2nn0	$$⊢2\in {\mathbb{N}}_0$$
7		eqid	$$⊢12=12$$
8		4cn	$$⊢4\in ℂ$$
9		2cn	$$⊢2\in ℂ$$
10		4p2e6	$$⊢4+2=6$$
11	8 9 10	addcomli	$$⊢2+4=6$$
12	5 6 1 7 11	decaddi	$$⊢12+4=16$$
13	1 2 3 4 12	4t3lem	$$⊢4\cdot 4=16$$