pub fn main(world: World) -> Void raises {
    var outer: u32 = 0
    var count: u32 = 0
    while outer < 3 {
        var inner: u32 = 0
        while inner < 4 {
            count = count + 1
            inner = inner + 1
        }
        outer = outer + 1
    }
    if count == 12 {
        check world.out.write("nested loops ok\n")
    }
}