Theorem f1dm 5236

Description: The domain of a one-to-one mapping. (Contributed by NM, 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 5233	. 2 |- ( F : A -1-1-> B -> F Fn A )
2		fndm 5128	. 2 |- ( F Fn A -> dom F = A )
3	1, 2	syl 14	1 |- ( F : A -1-1-> B -> dom F = A )

Syntax hints:   -> wi 4   = wceq 1290   dom cdm 4454   Fn wfn 5025   -1-1->wf1 5027

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 105  ax-ia2 106

This theorem depends on definitions:  df-bi 116  df-fn 5033  df-f 5034  df-f1 5035

This theorem is referenced by:  fun11iun  5289  tposf12  6050  f1dmvrnfibi  6709  f1vrnfibi  6710  exmidfodomrlemim  6890  exmidsbthrlem  12215