as far as I know , SGML is the base of HTML , XML is the base of XHTML , and I know the code be used in XML then refered to XHTML , but about SGML , anyone shows me some commands of this kind ?and , could you fill for me the equivalence between ones belowXHTML -- HTMLXML -- ???XSLT -- ???XPATH -- ?????? - ??? ( if you find more )thanks !!!