Theorem fofun 5481

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 5480	. 2 |- ( F : A -onto-> B -> F : A --> B )
2		ffun 5410	. 2 |- ( F : A --> B -> Fun F )
3	1, 2	syl 14	1 |- ( F : A -onto-> B -> Fun F )

Syntax hints:   -> wi 4   Fun wfun 5252   -->wf 5254   -onto->wfo 5256

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 1461  ax-7 1462  ax-gen 1463  ax-ie1 1507  ax-ie2 1508  ax-8 1518  ax-11 1520  ax-4 1524  ax-17 1540  ax-i9 1544  ax-ial 1548  ax-i5r 1549  ax-ext 2178

This theorem depends on definitions:  df-bi 117  df-nf 1475  df-sb 1777  df-clab 2183  df-cleq 2189  df-clel 2192  df-in 3163  df-ss 3170  df-fn 5261  df-f 5262  df-fo 5264

This theorem is referenced by:  foimacnv  5522  resdif  5526  fococnv2  5530  focdmex  6172  ctssdccl  7177  suplocexprlem2b  7781  suplocexprlemmu  7785  suplocexprlemdisj  7787  suplocexprlemloc  7788  suplocexprlemub  7790  suplocexprlemlub  7791  ennnfonelemex  12631  ctinf  12647