Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Power Sets
Functions
ffrn
Next ⟩
ffrnb
Metamath Proof Explorer
Ascii
Unicode
Theorem
ffrn
Description:
A function maps to its range.
(Contributed by
Glauco Siliprandi
, 3-Mar-2021)
Ref
Expression
Assertion
ffrn
⊢
F
:
A
⟶
B
→
F
:
A
⟶
ran
⁡
F
Proof
Step
Hyp
Ref
Expression
1
ffn
⊢
F
:
A
⟶
B
→
F
Fn
A
2
dffn3
⊢
F
Fn
A
↔
F
:
A
⟶
ran
⁡
F
3
1
2
sylib
⊢
F
:
A
⟶
B
→
F
:
A
⟶
ran
⁡
F