using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace 测试3
{
    class Program
    {
        static void Main(string[] args)
        {
            for (uint i = 50; i <= 100; i++)
            {
                Prime p1 = new Prime(i);
                if (p1)
                {
                    Console.WriteLine((uint)i);
                }
            }
            Console.Read();
        }
       
    }

    class Prime
    {
        public uint x;
        public Prime(uint x1)
        {
            x = x1;
        }
               public static bool operator true(Prime p)
        {
            for(uint i=2;i<=p.x/2;i++)
                if(p.x % i==0)
                    return false ;
            return true;
        }
        public static bool operator false(Prime p)
        {
            for (uint i = 2; i <= p.x / 2; i++)
                if (p.x % i == 0)
                    return true ;
            return false;
        }
    }

}

 if (p1)什么意思？