Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Union
Ordinal isomorphism, Hartogs's theorem
oiexg
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oion
Metamath Proof Explorer
Ascii
Unicode
Theorem
oiexg
Description:
The order isomorphism on a set is a set.
(Contributed by
Mario Carneiro
, 25-Jun-2015)
Ref
Expression
Hypothesis
oicl.1
⊢
F
=
OrdIso
R
A
Assertion
oiexg
⊢
A
∈
V
→
F
∈
V
Proof
Step
Hyp
Ref
Expression
1
oicl.1
⊢
F
=
OrdIso
R
A
2
1
ordtype
⊢
R
We
A
∧
R
Se
A
→
F
Isom
E
,
R
dom
⁡
F
A
3
isof1o
⊢
F
Isom
E
,
R
dom
⁡
F
A
→
F
:
dom
⁡
F
⟶
1-1 onto
A
4
f1of1
⊢
F
:
dom
⁡
F
⟶
1-1 onto
A
→
F
:
dom
⁡
F
⟶
1-1
A
5
2
3
4
3syl
⊢
R
We
A
∧
R
Se
A
→
F
:
dom
⁡
F
⟶
1-1
A
6
f1f
⊢
F
:
dom
⁡
F
⟶
1-1
A
→
F
:
dom
⁡
F
⟶
A
7
f1dmex
⊢
F
:
dom
⁡
F
⟶
1-1
A
∧
A
∈
V
→
dom
⁡
F
∈
V
8
fex
⊢
F
:
dom
⁡
F
⟶
A
∧
dom
⁡
F
∈
V
→
F
∈
V
9
6
7
8
syl2an2r
⊢
F
:
dom
⁡
F
⟶
1-1
A
∧
A
∈
V
→
F
∈
V
10
9
expcom
⊢
A
∈
V
→
F
:
dom
⁡
F
⟶
1-1
A
→
F
∈
V
11
5
10
syl5
⊢
A
∈
V
→
R
We
A
∧
R
Se
A
→
F
∈
V
12
1
oi0
⊢
¬
R
We
A
∧
R
Se
A
→
F
=
∅
13
0ex
⊢
∅
∈
V
14
12
13
eqeltrdi
⊢
¬
R
We
A
∧
R
Se
A
→
F
∈
V
15
11
14
pm2.61d1
⊢
A
∈
V
→
F
∈
V