## Calculus (3rd Edition)

$x$ is not a real number and/or $y$ is not an integer.
We set $A$ to refer to "$x$ is a real number" and $B$ to refer to "$y$ is an integer". Now, we have $A$ and $B$ as true. The negation of $A$ and $B$ will be false, that is, at least one of them is false, so we can say: $x$ is not a real number and/or $y$ is not an integer.