Boolean Symbols and Expressions

One more example: consider the statement:

We can drink coffee or tea and not eat any donuts, or just drink coffee.

This statement sounds quite odd and abstract, but we can still express it with a Boolean expression. If we denote $x = ($"$\text{drink coffee}$"$)$, $y = ($"$\text{drink tea}$"$)$, and $z = ($"$\text{eat donuts}$"$)$, the statement can be expressed as: $(x + y)z' + x$.