Theorem f1ofn

Description: A one-to-one onto mapping is function on its domain. (Contributed by NM, 12-Dec-2003)

	Ref	Expression
Assertion	f1ofn	$$⊢F:A\underset{1-1\; onto}{⟶}B\to FFnA$$

Proof

Step	Hyp	Ref	Expression
1		f1of	$$⊢F:A\underset{1-1\; onto}{⟶}B\to F:A⟶B$$
2	1	ffnd	$$⊢F:A\underset{1-1\; onto}{⟶}B\to FFnA$$