bounded_unsatisfied_string.chr

:- module(bounded_unsatisfied_string, [result/1]).
:- use_module(library(prelude)).

:- chr_constraint result(any).

% Only int and float overloads — no string variant.
:- class (gt(int, int) -> bool), (gt(float, float) -> bool).
gt(X, Y) -> X > Y.

:- function pick_max(T, T) -> T requiring gt(T, T) -> bool.

pick_max(X, Y) | gt(X, Y) -> X.
pick_max(_, Y) -> Y.

% Bound unsatisfied: there is no gt(string, string) -> bool.
result(R) <=> R is pick_max("a", "b").