using System;
using System.Console;

module LoopMultiple
{
    Zip3[T1, T2, T3] (x : list[T1], y : list[T2], z : list[T3]) :
list[T1 * T2 * T3]
    {
        |(x::xs, y::ys, z::zs) => (x, y, z)::Zip3(xs, ys, zs)
        |([], [], [])          => []
        |(_, _, [])            => throw ArgumentNullException()
        |(_, [], _)            => throw ArgumentNullException()
        |([], _, _)            => throw ArgumentNullException()
    }

    Main() : void
    {
        def first  = ['a', 'b', 'c'];
        def second = ["A", "B", "C"];
        def third  = [1, 2, 3];

        foreach ((x, y, z) in Zip3(first, second, third))
            WriteLine($"$x$y$z");
    }
}