Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Power Sets
Functions
intpreima
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fimacnvOLD
Metamath Proof Explorer
Ascii
Unicode
Theorem
intpreima
Description:
Preimage of an intersection.
(Contributed by
FL
, 28-Apr-2012)
Ref
Expression
Assertion
intpreima
⊢
Fun
⁡
F
∧
A
≠
∅
→
F
-1
⋂
A
=
⋂
x
∈
A
F
-1
x
Proof
Step
Hyp
Ref
Expression
1
intiin
⊢
⋂
A
=
⋂
x
∈
A
x
2
1
imaeq2i
⊢
F
-1
⋂
A
=
F
-1
⋂
x
∈
A
x
3
iinpreima
⊢
Fun
⁡
F
∧
A
≠
∅
→
F
-1
⋂
x
∈
A
x
=
⋂
x
∈
A
F
-1
x
4
2
3
eqtrid
⊢
Fun
⁡
F
∧
A
≠
∅
→
F
-1
⋂
A
=
⋂
x
∈
A
F
-1
x