This is great! Glad to see it.
display/1 is just what’s needed -some zero config, zero syntactic sugar representation.
Last time I gave a full ‘learn prolog’ workshop was in Dec. at Functional Conf. I used ‘implement complex arithmetic’ as a problem. Students struggled with the operators.
This is an old and complex debate, and will always side new users against veterans. Should we have syntactic sugar that makes the language read more naturally, or eschew it and have syntactic transparency.
If one still has a good grasp of the language, then one has syntactic transparency even in the face of sugar, and it becomes an aid. If one is struggling to learn, then it can be a source of confusion.
Giving the student a simple way to answer the ‘what does this represent’ question for themselves has pedagogic value as student centered learning.