dunno why, but fd/interval as written turns negative bounds into 0

https://github.com/clojure/core.logic/blob/master/src/main/clojure/clojure/core/logic/fd.clj#L363-L364

Aha 🙂

> non negative integer or more generally discrete constraints. These last constraints, sometimes also called finite domain constraints, are generally studied in the Constraint Satisfaction Problems (CSP)

Source: https://www.sciencedirect.com/topics/computer-science/finite-domain-constraint

So a finite domain is nonnegative by definition

Related question: https://stackoverflow.com/questions/13195493/core-logic-finite-domain-with-ve-values

There might be a reason related to increasing search space why negative numbers are excluded, but I can’t find it anywhere

But anyway for this specific problem I don’t need negative numbers

I don’t need to represent the input as maps