RosettaCodeData/Task/Ackermann-function/Elena/ackermann-function.elena

import extensions;

ackermann(m,n)
{
   if(n < 0 || m < 0)
   {
      InvalidArgumentException.raise()
   };

   m =>
      0 { ^n + 1 }
      ! {
         n =>
            0 { ^ackermann(m - 1,1) }
            ! { ^ackermann(m - 1,ackermann(m,n-1)) }
         }
}

public program()
{
   for(int i:=0; i <= 3; i += 1)
   {
      for(int j := 0; j <= 5; j += 1)
      {
         console.printLine("A(",i,",",j,")=",ackermann(i,j))
      }
   };

   console.readChar()
}