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:- module ho2.
:- interface.
:- import_module io.

:- pred main(io__state::di, io__state::uo) is det.

:- implementation.
:- import_module int.

main -->
    { p(0, 3, Y0) },
    { p(1, 3, Y1) },
    { p(2, 4, Y2) },
    io__write_int(Y0),
    io__write_string(", "),
    io__write_int(Y1),
    io__write_string(", "),
    io__write_int(Y2),
    io__nl.

:- pred p(int::in, int::in, int::out) is det.

p(_, X, Y) :-
    C = (pred(A::in, B::out) is det :- B = A * X),
    q(C, X, Y).

:- pred q(pred(int, int)::in(pred(in, out) is det), int::in, int::out) is det.

q(C, X, Y) :-
    C(X * X, Y).