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 ∈ ℂ ∧ B ∈ ℂ → A + B = B + A
2 ax-addf ⊢ + : ℂ × ℂ ⟶ ℂ
3 2 fdmi ⊢ dom ⁡ + = ℂ × ℂ
4 3 ndmovcom ⊢ ¬ A ∈ ℂ ∧ B ∈ ℂ → A + B = B + A
5 1 4 pm2.61i ⊢ A + B = B + A