Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - start with the Axiom of Extensionality
Restricted quantification
rsp
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rspa
Metamath Proof Explorer
Ascii
Unicode
Theorem
rsp
Description:
Restricted specialization.
(Contributed by
NM
, 17-Oct-1996)
Ref
Expression
Assertion
rsp
⊢
∀
x
∈
A
φ
→
x
∈
A
→
φ
Proof
Step
Hyp
Ref
Expression
1
df-ral
⊢
∀
x
∈
A
φ
↔
∀
x
x
∈
A
→
φ
2
sp
⊢
∀
x
x
∈
A
→
φ
→
x
∈
A
→
φ
3
1
2
sylbi
⊢
∀
x
∈
A
φ
→
x
∈
A
→
φ