anchor.diff:  booleanFunctions returns [BooleanValue retval]
   options {backtrack=true; memoize=true;}	
   	: s1=calcExpr n=keyNOT? keyCONTAINS s2=calcExpr		
  -							{retval = new ContainsStmt($s1.retval, ($n.text != null), $s2.retval);}
  -	| s1=calcExpr n=keyNOT? keyLIKE s2=calcExpr 	{retval = new LikeStmt($s1.retval, ($n.text != null), $s2.retval);}
  +							{retval = new ContainsStmt($s1.retval, ($n.retval!=null), $s2.retval);}
  +	| s1=calcExpr n=keyNOT? keyLIKE s2=calcExpr 	{retval = new LikeStmt($s1.retval, ($n.retval!=null), $s2.retval);}
   	| s1=calcExpr n=keyNOT? keyBETWEEN s2=calcExpr keyAND s3=calcExpr		
  -							{retval = new DelegateBetweenStmt($s1.retval, ($n.text != null), $s2.retval, $s3.retval);}
  +							{retval = new DelegateBetweenStmt($s1.retval, ($n.retval!=null), $s2.retval, $s3.retval);}
   	| s1=calcExpr n=keyNOT? keyIN LPAREN l=exprList RPAREN			
  -							{retval = new DelegateInStmt($s1.retval, ($n.text != null), $l.retval);} 
  -	| s1=calcExpr keyIS n=keyNOT? keyNULL		{retval = new DelegateNullCompare(($n.text != null), $s1.retval);}	
  +							{retval = new DelegateInStmt($s1.retval, ($n.retval!=null), $l.retval);} 
  +	| s1=calcExpr keyIS n=keyNOT? keyNULL		{retval = new DelegateNullCompare(($n.retval!=null), $s1.retval);}	
   	;
   
   valueFunctions returns [GenericValue retval]
  
positive.code: 
  familyMapping returns [FamilyMapping retval]
  	: f=simpleId (keyINCLUDE d=keyUNMAPPED)? (LPAREN c=columnDefinitionnList RPAREN)? 
  							{retval = new FamilyMapping($f.text,  $d.text!=null, $c.retval);};
  
  columnDefinitionnList returns [List<ColumnDefinition> retval]
  @init {retval = Lists.newArrayList();}
  
negative.code: keyMAPPINGS                     : {isKeyword(input, "MAPPINGS")}? ID;
  keyMAX                          : {isKeyword(input, "MAX")}? ID;
  keyNONE                         : {isKeyword(input, "NONE")}? ID;
  keyNULL                         : {isKeyword(input, "NULL")}? ID;
  keyON                           : {isKeyword(input, "ON")}? ID;
  keyOR                           : {isKeyword(input, "OR")}? ID;
  