anchor.diff:      : expression
       ;
   
  -condition_wrapper
  -    : expression
  -    ;
  -
   expression
       : cursor_expression
  -    | logical_and_expression ( OR logical_and_expression )*
  -    ;
  -
  -expression_wrapper
  -    : expression
  +    | logical_or_expression
  +    ;
  +
  +logical_or_expression
  +    : logical_and_expression
  +    | logical_or_expression OR logical_and_expression
       ;
   
   logical_and_expression
  -    : negated_expression ( AND negated_expression )*
  +    : negated_expression
  +    | logical_and_expression AND negated_expression
       ;
   
   negated_expression
  
positive.code: grammar plsql;
  
  swallow_to_semi
      : ~( ';' )+
      ;
  
  compilation_unit
  
negative.code:     ;
  
  searched_case_when_part
      : WHEN expression THEN (/*TODO{$case_statement::isStatement}?*/ seq_of_statements | expression)
      ;
  
  case_else_part
      : ELSE (/*{$case_statement::isStatement}?*/ seq_of_statements | expression)
      ;
  // $>
  
  