object <NAME> is ;
op "<"(integer,integer)->integer;

obj X = integer;
obj Y = integer and integer;

op "<"(x:X,y:Y)->boolean;

op main(x:X, y:Y) = (
    -- <(x,y);            -- Syntactically, I don't think this can ever work,
    -- "<"(x,y);          --  nor can this.
    x < y;                -- However, this line should type check OK, given the
                          --  above overload of "<".
);