Theorem f1dm 5261

Description: The domain of a one-to-one mapping. (Contributed by set.mm contributors, 8-Mar-2014.)

Assertion

Ref	Expression
f1dm	|- (F:A-1-1->B -> dom F = A)

Proof of Theorem f1dm

Step	Hyp	Ref	Expression
1		f1fn 5259	. 2 |- (F:A-1-1->B -> F Fn A)
2		fndm 5182	. 2 |- (F Fn A -> dom F = A)
3	1, 2	syl 15	1 |- (F:A-1-1->B -> dom F = A)

Syntax hints:   -> wi 4   = wceq 1642  dom cdm 4772   Fn wfn 4776  -1-1->wf1 4778

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8

This theorem depends on definitions:  df-bi 177  df-an 360  df-fn 4790  df-f 4791  df-f1 4792

This theorem is referenced by:  fun11iun  5305