Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Power Sets
Functions
fnfvelrn
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ffvelrn
Metamath Proof Explorer
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Theorem
fnfvelrn
Description:
A function's value belongs to its range.
(Contributed by
NM
, 15-Oct-1996)
Ref
Expression
Assertion
fnfvelrn
⊢
F
Fn
A
∧
B
∈
A
→
F
⁡
B
∈
ran
⁡
F
Proof
Step
Hyp
Ref
Expression
1
fvelrn
⊢
Fun
⁡
F
∧
B
∈
dom
⁡
F
→
F
⁡
B
∈
ran
⁡
F
2
1
funfni
⊢
F
Fn
A
∧
B
∈
A
→
F
⁡
B
∈
ran
⁡
F