(* l06 - expressions with keywords *)

program     = [ 'CONST' { id '=' ( number | id ) ';' } ]
              [ 'VAR' { id ':' id ';' } ]
              'BEGIN' statement { ';' statement } '.' .
statement   = [ id ':=' expression | 'WRITE' expression ] .
expression  = simplexpr [ relop simplexpr ] .
simplexpr   = [ '+' | '-' ] term { addop term } .
term        = factor { mulop factor } .
factor      = number | id | '(' expression ')' | '~' factor .

relop       = '=' | '#' | '<>' | '<' | '<=' | '>' | '>=' .
addop       = '+' | '-' | '|' .
mulop       = '*' | '/' | '&' .

(*
l06 = l05 + keywords

2010-07-08, v00:
No control structures without keywords, so keywords first.


2010-07-13, v01:
Only non-functional modifications:
- Prsr: IF -> CASE where appropriate
- Scnr: TSymbol ordered for parser convenience (OR -> range), sExcl removed

*)