anchor.diff:  K_MORE: M O R E;
   K_IMPORTANT: I M P O R T A N T;
   K_THAN: T H A N;
  +K_SAMPLE: S A M P L E
  +K_RANDOMSUBSETS: R A N D O M '_' S U B S E T S
  +K_COUNT: C O U N T
  +K_DIMENSION: D I M E N S I O N
   
   
   
  
positive.code:  : K_SELECT  ( K_DISTINCT | K_ALL )? (top_keyword)? select_List_Item ( ',' select_List_Item  )*
     ( K_FROM ( table_List_Item ( ',' table_List_Item )* | join_clause ) )?
     ( K_WHERE expr )?
     ( K_SKYLINE K_OF exprSkyline )?
   ;
  
  type_name : name+ ( '(' signed_number ')' | '(' signed_number ',' signed_number ')' )?
  
negative.code:  | K_MORE
   | K_IMPORTANT
   | K_THAN
   | K_SAMPLE
   | K_RANDOMSUBSETS
   | K_COUNT
   | K_DIMENSION
   ;
  
  
  