The relation R on Z is defined by (x,y) in R if and only if x-y is even. Write $\displaystyle R \cap (\{1,2,3\}x\{1,2,3\})$ as a set by listing its elements.

The $\displaystyle \cap$ confuses me. Is the question asking which elements of the given set are in R? Then that would be $\displaystyle (\{1,1\},\{2,2\},\{3,3\},\{1,3\})$.