Aus Online Mathematik Brückenkurs 2

In words, the inequality says that the distance \displaystyle |z-i| between \displaystyle z and \displaystyle i should be strictly greater than 2 and less than or equal to 3. This means that the inequality defines an annular set having an inner radius of 2 and outer radius of 3, with centre at \displaystyle i.

The inner dashed circle is not included in the set; on the other hand, the outer solid circle does.