Metamath Proof Explorer


Theorem addcomgi

Description: Generalization of commutative law for addition. Simplifies proofs dealing with vectors. However, it is dependent on our particular definition of ordered pair. (Contributed by Andrew Salmon, 28-Jan-2012) (Revised by Mario Carneiro, 6-May-2015)

Ref Expression
Assertion addcomgi
|- ( A + B ) = ( B + A )

Proof

Step Hyp Ref Expression
1 addcom
 |-  ( ( A e. CC /\ B e. CC ) -> ( A + B ) = ( B + A ) )
2 ax-addf
 |-  + : ( CC X. CC ) --> CC
3 2 fdmi
 |-  dom + = ( CC X. CC )
4 3 ndmovcom
 |-  ( -. ( A e. CC /\ B e. CC ) -> ( A + B ) = ( B + A ) )
5 1 4 pm2.61i
 |-  ( A + B ) = ( B + A )