public static bool my_concat_atom(PlTermV term1)
        {
            System.Diagnostics.Debug.Print("my_concat_atom called with term - {0}", term1.ToString());

            int    arity   = term1.Size;
            string sRet    = "";
            PlTerm termOut = term1[arity - 1];

            for (int i = 0; i < arity - 1; i++)
            {
                sRet += term1[i].ToString();
            }
            termOut.Unify(sRet);
            return(true);
        }