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 B A + B = B + A
2 ax-addf + : ×
3 2 fdmi dom + = ×
4 3 ndmovcom ¬ A B A + B = B + A
5 1 4 pm2.61i A + B = B + A