For example:
R → R bar R|RR|R star|(R)|a|b
construct an equivalent unambiguous grammar: R → S|RbarS S→T|ST T → U|Tstar U→a|b|(R)
How about Eliminate left-recursion for R → R bar R|RR|R star|(R)|a|b ?
What's the different between Eliminate left-recursion and construct an equivalent unambiguous grammar?