Dear Essam,

As you know, BNF is used to describe the sequence of characters that make up 
a valid message/document/language etc.  The core XML document uses EBNF to 
describe what a valid XML document looks like.  If you have a valid (i.e. 
well-formed) XML document, XML Schema allows you to specify whether that 
particular instance of XML is valid according to your requirements or not.

Hence, if you are using XML Schema to define an XML based language, you do 
not need to define the BNF also.

(Note that the definition of the term 'valid' above is _not_ always 
according to the formal definition of valid in XML Schema.)

HTH,

Pete.
--
=============================================
Pete Cordell
Tech-Know-Ware Ltd
                         for XML to C++ data binding visit
                         http://www.tech-know-ware.com/lmx
                         (or http://www.xml2cpp.com)
=============================================

----- Original Message ----- 
From: "Essam Mansour" <essam.mansour@g...>
To: <xmlschema-dev@w...>; <www-xml-schema-comments@w...>; 
<xml-dev@l...>
Sent: Monday, March 06, 2006 1:36 PM
Subject: [xml-dev] XML Schema and BNF


Dear All,

I am designing an XML-based language. I am using the XML Schema to
define the syntax of the language.

I would like to know whether the XML Schema could be used as a
substitution or an alternative to the BNF or not?
Could you tell me references addressing that?


Thanks you in advance for your help.
I am looking forward to your reply


--
Regards,

Essam Mansour