[1] : The Free On-line Dictionary of Computing (27 SEP 03)

backus-naur form
     
         bnf, originally "backus normal form" a
        formal metasyntax used to express context-free grammars.
        backus normal form was renamed backus-naur form at the
        suggestion of donald knuth.
     
        bnf is one of the most commonly used metasyntactic notations
        for specifying the syntax of programming languages, command
        sets, and the like.  it is widely used for language
        descriptions but seldom documented anywhere how do you
        document a metasyntax?, so that it must usually be learned
        by osmosis but see rfc 2234.
     
        consider this bnf for a us postal address:
     
          ::=   
     
          ::=  |  "."
     
          ::=    
        	       |  
     
          ::=    
     
          ::=  ","   
     
        this translates into english as: "a postal-address consists of
        a name-part, followed by a street-address part, followed by a
        zip-code part.  a personal-part consists of either a first
        name or an initial followed by a dot.  a name-part consists of
        either: a personal-part followed by a last name followed by an
        optional "jr-part" jr., sr., or dynastic number and
        end-of-line, or a personal part followed by a name part this
        rule illustrates the use of recursion in bnfs, covering the
        case of people who use multiple first and middle names and/or
        initials.  a street address consists of an optional apartment
        specifier, followed by a street number, followed by a street
        name.  a zip-part consists of a town-name, followed by a
        comma, followed by a state code, followed by a zip-code
        followed by an end-of-line."
     
        note that many things such as the format of a personal-part,
        apartment specifier, or zip-code are left unspecified.  these
        lexical details are presumed to be obvious from context or
        specified somewhere nearby.
     
        there are many variants and extensions of bnf, possibly
        containing some or all of the regexp wild cards such as
        "" or "+".  ebnf is a common one.  in fact the example
        above isn't the pure form invented for the algol 60 report.
        "" was introduced a few years later in ibm's pl/i
        definition but is now universally recognised.  abnf is
        another extension.
     
        1997-11-23
     
     
see also:
metasyntax context-free grammars donald knuth syntax rfc 2234 regexp 
wild cards ebnf algol 60 ibm pl/i 
abnf 

Combining Form >> C Words
Combining Form, definition of term: Combining Form
combining+form_pag1.html

Art Form >> A Words
Art Form, definition of term: Art Form
art+form_pag1.html