Metamath Proof Explorer

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 e. NN0
2 0nn0 
 |-  0 e. NN0
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