Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Union
The mapping operation
elpmi
Next ⟩
pmfun
Metamath Proof Explorer
Ascii
Unicode
Theorem
elpmi
Description:
A partial function is a function.
(Contributed by
Mario Carneiro
, 15-Sep-2015)
Ref
Expression
Assertion
elpmi
⊢
F
∈
A
↑
𝑝𝑚
B
→
F
:
dom
⁡
F
⟶
A
∧
dom
⁡
F
⊆
B
Proof
Step
Hyp
Ref
Expression
1
n0i
⊢
F
∈
A
↑
𝑝𝑚
B
→
¬
A
↑
𝑝𝑚
B
=
∅
2
fnpm
⊢
↑
𝑝𝑚
Fn
V
×
V
3
2
fndmi
⊢
dom
⁡
↑
𝑝𝑚
=
V
×
V
4
3
ndmov
⊢
¬
A
∈
V
∧
B
∈
V
→
A
↑
𝑝𝑚
B
=
∅
5
1
4
nsyl2
⊢
F
∈
A
↑
𝑝𝑚
B
→
A
∈
V
∧
B
∈
V
6
elpm2g
⊢
A
∈
V
∧
B
∈
V
→
F
∈
A
↑
𝑝𝑚
B
↔
F
:
dom
⁡
F
⟶
A
∧
dom
⁡
F
⊆
B
7
5
6
syl
⊢
F
∈
A
↑
𝑝𝑚
B
→
F
∈
A
↑
𝑝𝑚
B
↔
F
:
dom
⁡
F
⟶
A
∧
dom
⁡
F
⊆
B
8
7
ibi
⊢
F
∈
A
↑
𝑝𝑚
B
→
F
:
dom
⁡
F
⟶
A
∧
dom
⁡
F
⊆
B