Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Power Sets
Functions
fofun
Next ⟩
fofn
Metamath Proof Explorer
Ascii
Unicode
Theorem
fofun
Description:
An onto mapping is a function.
(Contributed by
NM
, 29-Mar-2008)
Ref
Expression
Assertion
fofun
⊢
F
:
A
⟶
onto
B
→
Fun
⁡
F
Proof
Step
Hyp
Ref
Expression
1
fof
⊢
F
:
A
⟶
onto
B
→
F
:
A
⟶
B
2
1
ffund
⊢
F
:
A
⟶
onto
B
→
Fun
⁡
F