Theorem funforn 6122

Description: A function maps its domain onto its range. (Contributed by NM, 23-Jul-2004.)

Assertion

Ref	Expression
funforn	|- ( Fun A <-> A : dom A -onto-> ran A )

Proof of Theorem funforn

Step	Hyp	Ref	Expression
1		funfn 5918	. 2 |- ( Fun A <-> A Fn dom A )
2		dffn4 6121	. 2 |- ( A Fn dom A <-> A : dom A -onto-> ran A )
3	1, 2	bitri 264	1 |- ( Fun A <-> A : dom A -onto-> ran A )

Syntax hints:   <-> wb 196   dom cdm 5114   ran crn 5115   Fun wfun 5882   Fn wfn 5883   -onto->wfo 5886

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-9 1999  ax-ext 2602

This theorem depends on definitions:  df-bi 197  df-an 386  df-ex 1705  df-cleq 2615  df-fn 5891  df-fo 5894

This theorem is referenced by:  fimacnvinrn  6348  imacosupp  7335  ordtypelem8  8430  wdomima2g  8491  imadomg  9356  gruima  9624  oppglsm  18057  1stcrestlem  21255  dfac14  21421  qtoptop2  21502