Metamath Proof Explorer


Theorem 2p1e3

Description: 2 + 1 = 3. (Contributed by Mario Carneiro, 18-Apr-2015)

Ref Expression
Assertion 2p1e3
|- ( 2 + 1 ) = 3

Proof

Step Hyp Ref Expression
1 df-3
 |-  3 = ( 2 + 1 )
2 1 eqcomi
 |-  ( 2 + 1 ) = 3