</TT
	    ></FONT
	  ><TT
	  ><I
	    >y1&nbsp;x1</I
	    ></TT
	  ><BR
	  ><BR
	  ><TT
	  ><I
	    >combine&nbsp;</I
	    ></TT
	  ><FONT COLOR = "navy"
	  ><TT
	    ><B
	      >::&nbsp;</B
	      ></TT
	    ></FONT
	  ><TT
	  ><I
	    >BlockTable&nbsp;a&nbsp;</I
	    ></TT
	  ><BR
	  ><TT
	  >&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</TT
	  ><FONT COLOR = "navy"
	  ><TT
	    ><B
	      >-&gt;&nbsp;</B
	      ></TT
	    ></FONT
	  ><TT
	  ><I
	    >BlockTable&nbsp;b&nbsp;</I
	 