Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - start with the Axiom of Extensionality
The universal class
rspct
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rspcdf
Metamath Proof Explorer
Ascii
Unicode
Theorem
rspct
Description:
A closed version of
rspc
.
(Contributed by
Andrew Salmon
, 6-Jun-2011)
Ref
Expression
Hypothesis
rspct.1
⊢
Ⅎ
x
ψ
Assertion
rspct
⊢
∀
x
x
=
A
→
φ
↔
ψ
→
A
∈
B
→
∀
x
∈
B
φ
→
ψ
Proof
Step
Hyp
Ref
Expression
1
rspct.1
⊢
Ⅎ
x
ψ
2
df-ral
⊢
∀
x
∈
B
φ
↔
∀
x
x
∈
B
→
φ
3
eleq1
⊢
x
=
A
→
x
∈
B
↔
A
∈
B
4
3
adantr
⊢
x
=
A
∧
φ
↔
ψ
→
x
∈
B
↔
A
∈
B
5
simpr
⊢
x
=
A
∧
φ
↔
ψ
→
φ
↔
ψ
6
4
5
imbi12d
⊢
x
=
A
∧
φ
↔
ψ
→
x
∈
B
→
φ
↔
A
∈
B
→
ψ
7
6
ex
⊢
x
=
A
→
φ
↔
ψ
→
x
∈
B
→
φ
↔
A
∈
B
→
ψ
8
7
a2i
⊢
x
=
A
→
φ
↔
ψ
→
x
=
A
→
x
∈
B
→
φ
↔
A
∈
B
→
ψ
9
8
alimi
⊢
∀
x
x
=
A
→
φ
↔
ψ
→
∀
x
x
=
A
→
x
∈
B
→
φ
↔
A
∈
B
→
ψ
10
nfv
⊢
Ⅎ
x
A
∈
B
11
10
1
nfim
⊢
Ⅎ
x
A
∈
B
→
ψ
12
nfcv
⊢
Ⅎ
_
x
A
13
11
12
spcgft
⊢
∀
x
x
=
A
→
x
∈
B
→
φ
↔
A
∈
B
→
ψ
→
A
∈
B
→
∀
x
x
∈
B
→
φ
→
A
∈
B
→
ψ
14
9
13
syl
⊢
∀
x
x
=
A
→
φ
↔
ψ
→
A
∈
B
→
∀
x
x
∈
B
→
φ
→
A
∈
B
→
ψ
15
2
14
syl7bi
⊢
∀
x
x
=
A
→
φ
↔
ψ
→
A
∈
B
→
∀
x
∈
B
φ
→
A
∈
B
→
ψ
16
15
com34
⊢
∀
x
x
=
A
→
φ
↔
ψ
→
A
∈
B
→
A
∈
B
→
∀
x
∈
B
φ
→
ψ
17
16
pm2.43d
⊢
∀
x
x
=
A
→
φ
↔
ψ
→
A
∈
B
→
∀
x
∈
B
φ
→
ψ