Induced Group Product is Homomorphism iff Commutative/Corollary

Corollary to Induced Group Product is Homomorphism iff Commutative
Let $\struct {G, \circ}$ be a group.

Let $\phi: G \times G \to G$ be defined such that:
 * $\forall a, b \in G: \map \phi {a, b} = a \circ b$

Then $\phi$ is a homomorphism $G$ is abelian.

Proof
We have that $G$ is a subgroup of itself.

The result then follows from Induced Group Product is Homomorphism iff Commutative by putting $H_1 = H_2 = G$.