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()
}