I'm stuck on an undergraduate CS exercise: I am to translate "Everybody knows somebody who knows Alice" into predicate logic.
I'm having trouble bending my head around it (being a complete beginner), but this is what I'm thinking:
$x,y \in $ "the set of all people"
$A(y) = y$ knows Alice
$\forall x \exists !y A(y)$
However, this feels too cumbersome (if it's even valid), and I'm sure there must be a better, simpler way of doing it. Can anybody offer any suggestions?