Theorem fofun 5569

Description: An onto mapping is a function. (Contributed by NM, 29-Mar-2008.)

Assertion

Ref	Expression
fofun	|- ( F : A -onto-> B -> Fun F )

Proof of Theorem fofun

Step	Hyp	Ref	Expression
1		fof 5568	. 2 |- ( F : A -onto-> B -> F : A --> B )
2		ffun 5492	. 2 |- ( F : A --> B -> Fun F )
3	1, 2	syl 14	1 |- ( F : A -onto-> B -> Fun F )

Syntax hints:   -> wi 4   Fun wfun 5327   -->wf 5329   -onto->wfo 5331

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-11 1555  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-ext 2213

This theorem depends on definitions:  df-bi 117  df-nf 1510  df-sb 1811  df-clab 2218  df-cleq 2224  df-clel 2227  df-in 3207  df-ss 3214  df-fn 5336  df-f 5337  df-fo 5339

This theorem is referenced by:  foimacnv  5610  resdif  5614  fococnv2  5618  focdmex  6286  ctssdccl  7353  suplocexprlem2b  7977  suplocexprlemmu  7981  suplocexprlemdisj  7983  suplocexprlemloc  7984  suplocexprlemub  7986  suplocexprlemlub  7987  ennnfonelemex  13098  ctinf  13114