This is a nice overview: CLPFD and CLPZ: Prolog Integer Arithmetic

mother can be used in several ways. If both X and Y variables are uninitialized, then it looks for all mother relationships. If one of them is initialized, it looks for matching relationships. If both are initialized, it returns true if such a relationship exists.

Depends on how you want to define your domain knowledge.

The thing you need to define for sure is the predicate mother/2 (Which has arity 2, or in other words, two arguments). From then on, multiple options are available:

1. Take mother(X, Y) as an “axiom”, and define mother terms for all elements:

mother(abel, eve).
mother(isaac, sarah).

2. Derive mother(X, Y) from female(X) and parent(X, Y) terms.

mother(X, Y) :- 
  parent(X, Y), 
  female(Y).

3. Smash the institutional gender power structures and define only parent/2 terms instead of mother/2 and father/2.

Brilliant!

I can confirm it’s Catppuccin Mocha. I am not currently aware of the background color issue, but I’ll look into the matter soon. Thanks for letting me know. Also how dare you. But thanks.

Point taken, but Big Tech systematically does equally bad things while disguising them behind DevRel, so I think it’s justified to poke fun at that.