Theorem fofun 5560

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 5559	. 2 ⊢ (𝐹:𝐴–onto→𝐵 → 𝐹:𝐴⟶𝐵)
2		ffun 5485	. 2 ⊢ (𝐹:𝐴⟶𝐵 → Fun 𝐹)
3	1, 2	syl 14	1 ⊢ (𝐹:𝐴–onto→𝐵 → Fun 𝐹)

Syntax hints:   → wi 4  Fun wfun 5320  ⟶wf 5322  –onto→wfo 5324

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 1495  ax-7 1496  ax-gen 1497  ax-ie1 1541  ax-ie2 1542  ax-8 1552  ax-11 1554  ax-4 1558  ax-17 1574  ax-i9 1578  ax-ial 1582  ax-i5r 1583  ax-ext 2213

This theorem depends on definitions:  df-bi 117  df-nf 1509  df-sb 1811  df-clab 2218  df-cleq 2224  df-clel 2227  df-in 3206  df-ss 3213  df-fn 5329  df-f 5330  df-fo 5332

This theorem is referenced by:  foimacnv  5601  resdif  5605  fococnv2  5609  focdmex  6277  ctssdccl  7310  suplocexprlem2b  7934  suplocexprlemmu  7938  suplocexprlemdisj  7940  suplocexprlemloc  7941  suplocexprlemub  7943  suplocexprlemlub  7944  ennnfonelemex  13040  ctinf  13056