Problem Statement

Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers.
Otherwise, generate and print a second random number before restarting the loop.
If the number 10 is never generated as the first number in a loop, loop forever.

Let's start with the solution:

using System;
using System.Console;
using Nemerle.Imperative;

module Break
{
    Main() : void
    {
        def rnd = Random();
        while (true)
        {
            def a = rnd.Next(20);
            WriteLine(a);
            when (a == 10) break;
            def b = rnd.Next(20);
            WriteLine(b);
        }
    }
}