import java.util.* ;
   import java.net.* ;
   import java.io.*;
   import java.lang.*;


// to be able to  read from the input
// *implements* Runnable is needed because the run method of this class 
//is activated by a thread

S = <service> Service *implements* Runnable.

Service : Basic_Service | Repeatition | Time_Limit | Sequential_Execution | Concurrent_Execution .

Basic_Service = "url" "(" <address> Address ")". 

// first and second have been inserted to make the cd LL(1)

Sequential_Execution = "first" <first> S "?" "second" <second> S .

Address = <string>String.

Repeatition = "repeat" "(" <repeat>S ")".

Time_Limit = "timeout" "(" <time>Time "," <on>Block ")" .

Time = <l>long.

Block : S | Stall.

Stall = "stall".

// Main and Thread have been inserted to make the cd LL(1)

Concurrent_Execution = "Main"<main>S "|" "Thread"<thread>S.

// *noparse* must be here becase of the use of URL and InputStream classe

*noparse*Visitor = <rv>RepeatCheckingVisitor <lv>LimitCheckingVisitor          <date>long <page>StringBuffer <urlConn>URL <stream>InputStream <next>int       <active>boolean <s>Thread <concurrent>boolean <sequentialStack>Stack <concurrentStack>Stack.

RepeatCheckingVisitor = <date>long <lv>LimitCheckingVisitor <v>Visitor.
 

LimitCheckingVisitor = <limitFlag>boolean <limit>long <date>Long <limitStack>Stack<v>Visitor.

TimeCheckingVisitor = <flag>int <time>long <pretime>long <condition>boolean.

Main=.