bounded_unresolved_arg.chr

:- module(bounded_unresolved_arg, [result/2]).
:- use_module(library(prelude)).

:- chr_constraint result(any, any).

:- class (gt(int, int) -> bool), (gt(float, float) -> bool).
gt(X, Y) -> X > Y.

:- function pick(T, T) -> T requiring gt(T, T) -> bool.
pick(X, _) -> X.

% Polymorphic use: X is unconstrained at the call site, so the bound's
% substitution stays partial and discharges silently per the gradual
% guarantee. Type-check should accept this with no errors.
result(X, R) <=> R is pick(X, X).