(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Let Ts denote the set of points in the x; y plane lying on the square whose

vertices are (-s; s), (s; s), (s;-s), (-s;-s), but not interior to the square. For

example, T1 consists of the vertices (-1; 1), (1; 1), (1;-1), (-1;-1) and the

four line segments joining them. Let

S = union of Ts, where s is an element of positive real numbers

Determine a set J, that is not dened in terms of unions, that equals S. Prove

that S and J are equal.

Please help. I have no idea how to start that problem. What I figure out is that J=AuBuCuD, where set A={ (x,y)| (x,y)=(s,y), for -s≤y≤s} B={(x,y)| (x,y)=(-s,y), for -s≤y≤s}, C={(x,y)| (x,y)=(x,s), for -s≤x≤s}, D={(x,y)| (x,y)=(x,-s), for -s≤x≤s}

I do not know how to write down set S in different form and how to prove that J=S

2. Relevant equations

3. The attempt at a solution

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# Homework Help: Abstract math prove involwing sets

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