Metamath Proof Explorer


Theorem f1of

Description: A one-to-one onto mapping is a mapping. (Contributed by NM, 12-Dec-2003)

Ref Expression
Assertion f1of ⊢ F : A ⟶ 1-1 onto B → F : A ⟶ B

Proof

Step Hyp Ref Expression
1 f1of1 ⊢ F : A ⟶ 1-1 onto B → F : A ⟶ 1-1 B
2 f1f ⊢ F : A ⟶ 1-1 B → F : A ⟶ B
3 1 2 syl ⊢ F : A ⟶ 1-1 onto B → F : A ⟶ B