Kindayr
- 159
- 0
Homework Statement
Let \sigma (E)=\{(x,y):x-y\in E\} for any E\subseteq\mathbb{R}. If E has measure zero, then \sigma (E) has measure zero.
The Attempt at a Solution
I'm trying to show that if \sigma (E) is not of measure zero, then there exists a point in E such that \sigma (\{e\}) that has positive measure. But i don't know if this actually proves the question.
I have already shown that if E open or a G_{\delta} set, then \sigma (E) is also measurable. Can I use these to solve this?
Any help is appreciated.