anchor.diff:  		(
   			DOT (NEWLINE)*
   			e=member_reference_expression[e]
  +			(NULLABLE_SUFFIX {
  +					ue = new UnaryExpression(e.LexicalInfo);
  +					ue.Operator = UnaryOperatorType.SafeAccess;
  +					ue.Operand = e;
  +					e = ue;
  +				}
  +			)?
   		)
   		|
   		(
  
positive.code: 				slice[se] (COMMA slice[se])*
  			)
  			RBRACK
  		)
  		|
  		(
  
negative.code: 		TypeReferenceCollection genericArguments = null;
  		Expression initializer = null;
  	} :
  	e=safe_atom
  	( options { greedy=true; }:
  		(
  			lbrack:LBRACK
  