Theorem fofun 5132

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 5131	. 2 ⊢ (𝐹:𝐴–onto→𝐵 → 𝐹:𝐴⟶𝐵)
2		ffun 5073	. 2 ⊢ (𝐹:𝐴⟶𝐵 → Fun 𝐹)
3	1, 2	syl 14	1 ⊢ (𝐹:𝐴–onto→𝐵 → Fun 𝐹)

Syntax hints:   → wi 4  Fun wfun 4920  ⟶wf 4922  –onto→wfo 4924

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-5 1377  ax-7 1378  ax-gen 1379  ax-ie1 1423  ax-ie2 1424  ax-8 1436  ax-11 1438  ax-4 1441  ax-17 1460  ax-i9 1464  ax-ial 1468  ax-i5r 1469  ax-ext 2064

This theorem depends on definitions:  df-bi 115  df-nf 1391  df-sb 1687  df-clab 2069  df-cleq 2075  df-clel 2078  df-in 2980  df-ss 2987  df-fn 4929  df-f 4930  df-fo 4932

This theorem is referenced by:  foimacnv  5169  resdif  5173  fococnv2  5177  fornex  5767