> I don't know very much about Prolog though, so maybe there's a lot of crucial parts missing here.

An easy way to find out if your implementation works is to try out the `likes.pl`[1] example found in the SWI-Prolog "Getting started quickly"[0] documentation.

0 - https://www.swi-prolog.org/pldoc/man?section=quickstart

1 - https://raw.githubusercontent.com/SWI-Prolog/swipl-devel/mas...