Factorial in pure LINQ

Fact.cs

private class Wrap<T>
{
    public readonly Func<Wrap<T>, T> It;

    public Wrap(Func<Wrap<T>, T> it)
    {
        It = it;
    }
}

public static Func<T, U> Y<T, U>(Func<Func<T, U>, Func<T, U>> f)
{
    Func<Wrap<Func<T, U>>, Func<T, U>> g = wx => f(wx.It(wx));
    return g(new Wrap<Func<T, U>>(wx => f(y => wx.It(wx)(y))));
}

public static void Main()
{
    var query = from n in Enumerable.Range(0, 10)
        let computeFact = (Func<Func<int, int>, Func<int, int>>) (f => n1 => n1 == 0 ? 1 : (n1 * f(n1 - 1)))
        let fact = Y(computeFact)
        select new {X = fact(n)};
}