private void CalculateButt_Click(object sender, EventArgs e)
        {
            try
            {
                if (UnionRad.Checked)
                {
                    if (!InfixBox.Text.Equals(""))
                    {
                        String   infix  = InfixBox.Text;
                        String   posfix = Postfix.ConvertToPostFix(infix);
                        ArraySet res    = UnionAndIntersResult(posfix);
                        ResultBox.Text = res.toString();
                    }
                }

                if (PowerSetRad.Checked)
                {
                    ArraySet res = UnionAndIntersResult(Postfix.ConvertToPostFix(InfixBox.Text));
                    ResultBox.Text = ArraySet.getPowerSet(res);
                }
                if (SubSetRad.Checked)
                {
                    String   expression = InfixBox.Text;
                    String   temp       = "";
                    ArraySet temp1      = null;
                    ArraySet temp2;
                    foreach (char i in expression.ToCharArray())
                    {
                        if (i == 'c')
                        {
                            temp1 = UnionAndIntersResult(Postfix.ConvertToPostFix(temp));
                            temp  = "";
                        }
                        else
                        {
                            temp += i;
                        }
                    }
                    temp2          = UnionAndIntersResult(Postfix.ConvertToPostFix(temp));
                    ResultBox.Text = Convert.ToString(ArraySet.isSubsetOf(temp1, temp2));
                }
                if (CartesianRad.Checked)
                {
                    String expression = InfixBox.Text;
                    expression = expression.Replace('(', ' ');
                    expression = expression.Replace(')', ' ');
                    expression = expression.Replace('x', ' ');
                    int count = 0;
                    foreach (char i in expression.ToArray())
                    {
                        if (getIndexFromChar(i) != -1)
                        {
                            count++;
                        }
                    }
                    ArraySet[] tempSetList = new ArraySet[count];
                    count = 0;
                    foreach (char i in expression.ToArray())
                    {
                        if (getIndexFromChar(i) != -1)
                        {
                            tempSetList[count] = setList[getIndexFromChar(i)];
                            if (tempSetList[count].size() == 0)
                            {
                                ResultBox.Text = "Error : Cartesian product with an empty set";
                                return;
                            }
                            count++;
                        }
                    }
                    ResultBox.Text = ArraySet.Cartesian(tempSetList);
                }
            }catch (Exception ex)
            {
                MessageBox.Show("Error : Incorrect Input" + " : " + ex.Message);
            }
        }