Theorem 10p10e20

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

	Ref	Expression
Assertion	10p10e20	⊢ ( ; 1 0 + ; 1 0 ) = ; 2 0

Proof

Step	Hyp	Ref	Expression
1		1nn0	⊢ 1 ∈ ℕ0
2		0nn0	⊢ 0 ∈ ℕ0
3		eqid	⊢ ; 1 0 = ; 1 0
4		1p1e2	⊢ ( 1 + 1 ) = 2
5		00id	⊢ ( 0 + 0 ) = 0
6	1 2 1 2 3 3 4 5	decadd	⊢ ( ; 1 0 + ; 1 0 ) = ; 2 0