Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Power Sets
Relations
elima2
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elima3
Metamath Proof Explorer
Ascii
Unicode
Theorem
elima2
Description:
Membership in an image. Theorem 34 of
Suppes
p. 65.
(Contributed by
NM
, 11-Aug-2004)
Ref
Expression
Hypothesis
elima.1
⊢
A
∈
V
Assertion
elima2
⊢
A
∈
B
C
↔
∃
x
x
∈
C
∧
x
B
A
Proof
Step
Hyp
Ref
Expression
1
elima.1
⊢
A
∈
V
2
1
elima
⊢
A
∈
B
C
↔
∃
x
∈
C
x
B
A
3
df-rex
⊢
∃
x
∈
C
x
B
A
↔
∃
x
x
∈
C
∧
x
B
A
4
2
3
bitri
⊢
A
∈
B
C
↔
∃
x
x
∈
C
∧
x
B
A