Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Power Sets
Operations
fovrn
Next ⟩
fovrnda
Metamath Proof Explorer
Ascii
Unicode
Theorem
fovrn
Description:
An operation's value belongs to its codomain.
(Contributed by
NM
, 27-Aug-2006)
Ref
Expression
Assertion
fovrn
⊢
F
:
R
×
S
⟶
C
∧
A
∈
R
∧
B
∈
S
→
A
F
B
∈
C
Proof
Step
Hyp
Ref
Expression
1
opelxpi
⊢
A
∈
R
∧
B
∈
S
→
A
B
∈
R
×
S
2
df-ov
⊢
A
F
B
=
F
⁡
A
B
3
ffvelrn
⊢
F
:
R
×
S
⟶
C
∧
A
B
∈
R
×
S
→
F
⁡
A
B
∈
C
4
2
3
eqeltrid
⊢
F
:
R
×
S
⟶
C
∧
A
B
∈
R
×
S
→
A
F
B
∈
C
5
1
4
sylan2
⊢
F
:
R
×
S
⟶
C
∧
A
∈
R
∧
B
∈
S
→
A
F
B
∈
C
6
5
3impb
⊢
F
:
R
×
S
⟶
C
∧
A
∈
R
∧
B
∈
S
→
A
F
B
∈
C