anchor.diff:  		]
   	    ;
   	
  -swapstmt { int var1,var2; }
  +swapstmt { int var1; int var2; }
   	: SWAPSYM
   	  variable(&var1)
   	  ','
  
positive.code: 	| /* empty */
  	;
  
  letstmt { int var,exp; }
  	:	LETSYM		
  		variable(&var)		 { save_address(); }
  		'=' expression(&exp)  	 { assign(var,exp); }
  
negative.code: 		'=' expression(&exp)	 { assign(var,exp); }
  	;
  
  lineinputstmt { int var; int intv; }
  	: 	LINESYM
  		[ INPUTSYM
  	  	  semiprompt		 { setchannel(-1); }
  