Metamath Proof Explorer


Theorem elmapfun

Description: A mapping is always a function. (Contributed by Stefan O'Rear, 9-Oct-2014) (Revised by Stefan O'Rear, 5-May-2015)

Ref Expression
Assertion elmapfun ⊢ A ∈ B C → Fun ⁡ A

Proof

Step Hyp Ref Expression
1 elmapi ⊢ A ∈ B C → A : C ⟶ B
2 1 ffund ⊢ A ∈ B C → Fun ⁡ A