Maybe try a Ruby Kanren implementation:

https://minikanren.org/

uKanren is conceptually small and simple, here's a Ruby implementation: https://github.com/jsl/ruby_ukanren

There are a bunch of libraries that will do this - here's one example of a python one: https://github.com/yuce/pyswip - and a ruby one: https://github.com/preston/ruby-prolog

I did try ruby-prolog. The deeper issue is that its just not prolog. Writing in actual prolog affords a lot of clarity and concision which would be quite noisy in ruby-prolog. To me, the difference was stark enough it wasn't worth any convenience already being in ruby was worth.

Porolog might be more to your liking.

https://www.rubydoc.info/gems/porolog#porolog-wiki