C# is a dynamically typed programming language

linkedlist.cs

using System;
//https://aphyr.com/posts/340-reversing-the-technical-interview

namespace jambox
{
    class Program
    {
        delegate dynamic V(dynamic d);
        static V cons(dynamic lhs, dynamic rhs) => (b) => b ? lhs : rhs;
        static dynamic nth(dynamic l, dynamic n) => n == 0 ? l(true) : nth(l(false), n-1);
        static dynamic reverse(dynamic l, dynamic rest = null) => 
            l(false) == null ? cons(l(true), rest) : reverse(l(false), cons(l(true), rest));
        static dynamic map(dynamic l, V fn) =>
            l == null ? null : cons(fn(l(true)), map(l(false), fn));
        static int len(dynamic l, dynamic i = null) => l == null ? i ?? 0 : len(l(false), i == null ? 1 : i+1);
        
        static void pretty_print(dynamic l) {
            var tlen = len(l);
            var i = 0;
            Console.Write("(");
            map(l, (V)((n) => {
                Console.Write($"{n}{(++i==tlen?"":", ")}");
                return 0;
            }));
            Console.WriteLine(")");
        } 
            
        
        static void Main(string[] args)
        {
            var v = cons(1, cons(2, cons(3, null)));
            pretty_print(v);
            Console.WriteLine(nth(v, 2));
            pretty_print(reverse(v));
            Console.WriteLine(v);
        }
    }
}