[antlr-interest] New to antlr pls help

[solmalik]

Hi there I am trying to write a formal grammar using antlr but am 
having some problems in getting the right syntax.  The grammr is to 
be used in order to parse process expression, some examples of the 
expressions are:

(a || b) ^ (a || c)

or 
(a;b)

or e sy b sy a

I have tried to capture the three different above forms in the 
grammar but am having trouble getting it right, is there anyone who 
has an idea on how to do it? Below is the code i have so far:

class P extends Parser;

startRule
	:   e:EQUATION
        {System.out.println("The eqn entered is, "+e.getText());}
    	;

class L extends Lexer;

EQUATION: OPEN (MINEQN)+ CLOSE
	;

OPEN:	'(' ;

CLOSE:	')' ;

MINEQN	: OPEN LETTER KEYWORD LETTER CLOSE (KEYWORD)?
	| OPEN LETTER KEYWORD LETTER CLOSE (KEYWORD LETTER)?
	| LETTER KEYWORD LETTER
	;

KEYWORD	:	';'
	|	'||'
	|	'sy'
	|	'rs'
	|	'^'
	|	'*'
	;	
	
LETTER	:  ('a' .. 'z' | 'A' .. 'Z'); 


 

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