anchor.diff:  
   
   header {
  +import sys
   
   from sslParser import SemanticException
   
  
positive.code: 		{ res = self.factory.make("Ref(_)", i) }
  //    | t:TEMP
  	| v:NAME
  		{
              try:
                  res = self.locals[-1][#v.getText()]
              except KeyError:
                  res = self.factory.make("Sym(_)", #v.getText())
  		}
      ;
  
  lvalue returns [res]
  
negative.code: 			{ res.append(e) }
          )*
       ;
  
  collect_temps returns [res]
  		{ res = {} }
  	: do_collect_temps[res]
  		{ res = res.keys() }
  	;
  
  do_collect_temps[res]
  	: n:NAME
  		{
              if #n.getText().startswith("tmp"):
                 res[#n.getText()] = None
  		}
  	| #( . ( do_collect_temps[res] )* )
  	;
  