Metamath Proof Explorer

Theorem 4t3e12

Description: 4 times 3 equals 12. (Contributed by Mario Carneiro, 19-Apr-2015)

Ref Expression
Assertion 4t3e12 
|- ( 4 x. 3 ) = ; 1 2

Proof

Step Hyp Ref Expression
1 4nn0 
 |-  4 e. NN0
2 2nn0 
 |-  2 e. NN0
3 df-3 
 |-  3 = ( 2 + 1 )
4 4t2e8 
 |-  ( 4 x. 2 ) = 8
5 8p4e12 
 |-  ( 8 + 4 ) = ; 1 2
6 1 2 3 4 5 4t3lem 
 |-  ( 4 x. 3 ) = ; 1 2