# Neither thick set nor syndetic set but piecewise syndetic set

I am finding an example, which is neither thick set nor syndetic set but piecewise syndetic set. After too many many trials I got nothing. Can you help me to find this example? Thank you.

• Please define "example" (of what?), "thick" and the unusual word "syndetic". – Dr. Lutz Lehmann Dec 2 at 9:22