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CIIM
2010 CIIM
Problem 3
CIIM 2010 Problem 3
CIIM 2010 Problem 3
Source:
June 9, 2016
CIIM
CIIM 2010
undergraduate
Problem Statement
A set
X
⊂
R
X\subset \mathbb{R}
X
⊂
R
has dimension zero if, for any
ϵ
>
0
\epsilon > 0
ϵ
>
0
there exists a positive integer
k
k
k
and intervals
I
1
,
I
2
,
.
.
.
,
I
k
I_1,I_2,...,I_k
I
1
,
I
2
,
...
,
I
k
such that
X
⊂
I
1
∪
I
2
∪
⋯
∪
I
k
X \subset I_1 \cup I_2 \cup \cdots \cup I_k
X
⊂
I
1
∪
I
2
∪
⋯
∪
I
k
with
∑
j
=
1
k
∣
I
j
∣
ϵ
<
ϵ
\sum_{j=1}^k |I_j|^{\epsilon} < \epsilon
∑
j
=
1
k
∣
I
j
∣
ϵ
<
ϵ
.Prove that there exist sets
X
,
Y
⊂
[
0
,
1
]
X,Y \subset [0,1]
X
,
Y
⊂
[
0
,
1
]
both of dimension zero, such that
X
+
Y
=
[
0
,
2
]
.
X+Y = [0,2].
X
+
Y
=
[
0
,
2
]
.
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