Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Union
The mapping operation
elpm2r
Next ⟩
elpmi
Metamath Proof Explorer
Ascii
Unicode
Theorem
elpm2r
Description:
Sufficient condition for being a partial function.
(Contributed by
NM
, 31-Dec-2013)
Ref
Expression
Assertion
elpm2r
⊢
A
∈
V
∧
B
∈
W
∧
F
:
C
⟶
A
∧
C
⊆
B
→
F
∈
A
↑
𝑝𝑚
B
Proof
Step
Hyp
Ref
Expression
1
fdm
⊢
F
:
C
⟶
A
→
dom
⁡
F
=
C
2
1
feq2d
⊢
F
:
C
⟶
A
→
F
:
dom
⁡
F
⟶
A
↔
F
:
C
⟶
A
3
1
sseq1d
⊢
F
:
C
⟶
A
→
dom
⁡
F
⊆
B
↔
C
⊆
B
4
2
3
anbi12d
⊢
F
:
C
⟶
A
→
F
:
dom
⁡
F
⟶
A
∧
dom
⁡
F
⊆
B
↔
F
:
C
⟶
A
∧
C
⊆
B
5
4
adantr
⊢
F
:
C
⟶
A
∧
C
⊆
B
→
F
:
dom
⁡
F
⟶
A
∧
dom
⁡
F
⊆
B
↔
F
:
C
⟶
A
∧
C
⊆
B
6
5
ibir
⊢
F
:
C
⟶
A
∧
C
⊆
B
→
F
:
dom
⁡
F
⟶
A
∧
dom
⁡
F
⊆
B
7
elpm2g
⊢
A
∈
V
∧
B
∈
W
→
F
∈
A
↑
𝑝𝑚
B
↔
F
:
dom
⁡
F
⟶
A
∧
dom
⁡
F
⊆
B
8
6
7
syl5ibr
⊢
A
∈
V
∧
B
∈
W
→
F
:
C
⟶
A
∧
C
⊆
B
→
F
∈
A
↑
𝑝𝑚
B
9
8
imp
⊢
A
∈
V
∧
B
∈
W
∧
F
:
C
⟶
A
∧
C
⊆
B
→
F
∈
A
↑
𝑝𝑚
B