Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - start with the Axiom of Extensionality
The universal class
rspccv
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rspcva
Metamath Proof Explorer
Ascii
Unicode
Theorem
rspccv
Description:
Restricted specialization, using implicit substitution.
(Contributed by
NM
, 2-Feb-2006)
Ref
Expression
Hypothesis
rspcv.1
⊢
x
=
A
→
φ
↔
ψ
Assertion
rspccv
⊢
∀
x
∈
B
φ
→
A
∈
B
→
ψ
Proof
Step
Hyp
Ref
Expression
1
rspcv.1
⊢
x
=
A
→
φ
↔
ψ
2
1
rspcv
⊢
A
∈
B
→
∀
x
∈
B
φ
→
ψ
3
2
com12
⊢
∀
x
∈
B
φ
→
A
∈
B
→
ψ