******** fig7.10 **********

	/* l_pos = start of left half, r_pos = start of right half */

	void
	merge( input_type a[], input_type tmp_array[], int l_pos, int r_pos, int right_end)
	{
		int i, left_end, num_elements, tmp_pos;

		left_end = r_pos - 1;
		tmp_pos = l_pos;
		num_elements = right_end - l_pos + 1;

		while( (l_pos <= left_end) && (r_pos <= right_end) )	/* main loop */
			if( a[l_pos] <= a[r_pos] )
				tmp_array[tmp_pos++] = a[l_pos++];
			else
				tmp_array[tmp_pos++] = a[r_pos++];
		while( l_pos <= left_end )	/* copy rest of first half */
			tmp_array[tmp_pos++] = a[l_pos++];
		while( r_pos <= right_end )	/* copy rest of second half */
			tmp_array[tmp_pos++] = a[r_pos++];
		for(i=1; i<=num_elements; i++, right_end-- )	/* copy tmp_array back */
			a[right_end] = tmp_array[right_end];
	}