a_main.chr

:- module(main, [classify/1, run/2, type(colors/0)]).
:- use_module(prelude).
:- chr_constraint run/2.
:- chr_type colors ---> red ; blue.

:- open_function classify/1.

% Equations declared in this module.
classify(red)   -> quote(color).
classify(blue)  -> quote(color).

run(X, R) <=>
    R is classify(X).