delete left recursion in a grammar

Question

I have this grammar:

agent
 = nil 
 | @ 
 | id 
 | act . agent
 | agent + agent
 | agent "|" agent
 | agent \ restriction
 |  agent [relabeling]
 | agent where agent_frame end
 | automation
 | (agent)

where the priorities are:

"where" < "+" < "|" < "\" < "." < "[" < "nil", "@"

I need to delete the left recursion respecting the priorities ( and write all in JavaCC).

Can you help me to delete recursion?

Answer 1

Dinesh thank you for the answer, your solution give me a conflict in JavaCC with (agent-postfix)*. I solved in this way:

agent=agent2 agent'
agent'= "where" agent_frame "end" agent' | epsilon

agent2= agent3 agent2'
agent2'= "+" agent3 agent2' | epsilon

agent3= agent4 agent3'
agent3'= "|" agent4 agent3' | epsilon

agent4 = agent5 agent4'
agent4'= "\" restriction agent4' | epsilon

agent5: act "." agent | agent6

agent6 = agent7 agent6'
agent6'= "[" relabeling "]" agent6' | epsilon

agent7= id | automaton | "(" agent ")" | "nil" | "@"

but I don't know if this solution is correct.

Thank you very much.

Regards Domenico