grammar Example_4_1;

/* 
eliminate left-recursivity
when finished, check the grammar Grammar -> Check Grammar (CTRL+r)
*/

init 	:   s '\n';

s
	:   s a 'b' | s b 'a' | S 'cc' | a 'a' b | 'bc' 
	;

a
    	: 'a' a 'a' |
	;   	
/* the same as

a
    	: 'a' a 'a' | epsilon
	;   	

epsilon 
	:
	;
*/

b
    	: b 'b' b | b
	;