anchor.diff:  
   // GRAMMAR OF A TUPLE PATTERN
   
  -tuple_pattern : ( tuple_pattern_element_list?)  ;
  -tuple_pattern_element_list : tuple_pattern_element | tuple_pattern_element ',' tuple_pattern_element_list  ;
  +tuple_pattern : '(' tuple_pattern_element_list? ')'  ;
  +tuple_pattern_element_list
  +	:	tuple_pattern_element (',' tuple_pattern_element)*
  +	;
   tuple_pattern_element : pattern  ;
   
   // GRAMMAR OF AN ENUMERATION CASE PATTERN
   
  -enum_case_pattern : type_identifier?. enum_case_name tuple_pattern? ;
  +enum_case_pattern : type_identifier? '.' enum_case_name tuple_pattern? ;
   
   // GRAMMAR OF A TYPE CASTING PATTERN
   
  
positive.code: // | Any punctuation except ( ,  ')' , '[' , ']' , { , or }
   ;
  
  
  // Expressions
  
  
  // GRAMMAR OF AN EXPRESSION
  
  expression_list : expression (',' expression)* ;
  
  expression
  	:	prefix_operator? postfix_expression
      |	in_out_expression
      |	expression binary_operator expression
      |	expression assignment_operator expression
      |	expression conditional_operator expression
      |	expression type_casting_operator
  	;
  
  // GRAMMAR OF A PREFIX EXPRESSION
  
negative.code: 
  // GRAMMAR OF A TYPE IDENTIFIER
  
  type_identifier : type_name generic_argument_clause? type_name generic_argument_clause? '.' type_identifier  ;
  type_name : identifier  ;
  
  // GRAMMAR OF A TUPLE TYPE
  