using System;
using System.Runtime.InteropServices;/* Provides mappings between C# and native code */

namespace NumericalAlgorithmsGroup
{
  class tanfunc
    {
      [DllImport("FLDLL214Z_nag.dll")]/* Import from DLL, the C# compiler provides a rudimentry check of the signature */
	public static extern double S07AAF(ref double x, ref int ifail);
      public static void Main()
	{
	  double tanresult;
	  int ifail = 1;
	  double x = Math.PI/4;
	  tanresult = S07AAF(ref x, ref ifail);
	  Console.WriteLine("tan pi/4 = {0, 4:f2}", tanresult);
	}
    }
}