Theorem 10p10e20

Description: 10 + 10 = 20. (Contributed by Mario Carneiro, 19-Apr-2015) (Revised by AV, 6-Sep-2021)

	Ref	Expression
Assertion	10p10e20	$$⊢10+10=20$$

Proof

Step	Hyp	Ref	Expression
1		1nn0	$$⊢1\in {\mathbb{N}}_0$$
2		0nn0	$$⊢0\in {\mathbb{N}}_0$$
3		eqid	$$⊢10=10$$
4		1p1e2	$$⊢1+1=2$$
5		00id	$$⊢0+0=0$$
6	1 2 1 2 3 3 4 5	decadd	$$⊢10+10=20$$