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Metamath Proof Explorer

Theorem f1fn

Description: A one-to-one mapping is a function on its domain. (Contributed by NM, 8-Mar-2014)

		Ref	Expression
	Assertion	f1fn	$⊢ F : A \underset{1-1}{⟶} B \to F Fn A$

Step	Hyp	Ref	Expression
1		f1f	$⊢ F : A \underset{1-1}{⟶} B \to F : A ⟶ B$
2	1	ffnd	$⊢ F : A \underset{1-1}{⟶} B \to F Fn A$