Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - start with the Axiom of Extensionality
Restricted quantification
reeanv
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3reeanv
Metamath Proof Explorer
Ascii
Unicode
Theorem
reeanv
Description:
Rearrange restricted existential quantifiers.
(Contributed by
NM
, 9-May-1999)
Ref
Expression
Assertion
reeanv
⊢
∃
x
∈
A
∃
y
∈
B
φ
∧
ψ
↔
∃
x
∈
A
φ
∧
∃
y
∈
B
ψ
Proof
Step
Hyp
Ref
Expression
1
exdistrv
⊢
∃
x
∃
y
x
∈
A
∧
φ
∧
y
∈
B
∧
ψ
↔
∃
x
x
∈
A
∧
φ
∧
∃
y
y
∈
B
∧
ψ
2
1
reeanlem
⊢
∃
x
∈
A
∃
y
∈
B
φ
∧
ψ
↔
∃
x
∈
A
φ
∧
∃
y
∈
B
ψ