using System;
using System.Globalization;
using System.Linq;
using System.Collections.Generic;
 
public class Test
{
 
 
	public static void Main()
	{
        double? previousValue = null;
        double? v1 = 1 + previousValue ?? 0;
        double? v2 = 1 + (previousValue ?? 0);
        Console.WriteLine("V1.Hasvalue? {0} V1.Value:{1}",v1.HasValue, v1.Value);
        Console.WriteLine("V2.Hasvalue? {0} V2.Value:{1}",v2.HasValue, v2.Value);
	}
}

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