anchor.diff:  
   ;
   simple_select:
  -	  SELECT  opt_all_clause into_clause/*??? unable to find in doc syntax like select  into sysrec * from system where name = new.sysname; - got from plpgsql.sql test script*/
  -	            opt_target_list into_clause from_clause where_clause group_clause  having_clause window_clause # simple_select_select
  -	| SELECT  distinct_clause target_list     into_clause from_clause where_clause group_clause  having_clause window_clause # simple_select_select
  +    /*??? unable to find in doc syntax like select  into sysrec * from system where name = new.sysname; - got from plpgsql.sql test script*/
  +	  SELECT
  +	        (
  +	            opt_all_clause  into_clause  opt_target_list
  +	            |distinct_clause target_list
  +	        )
  +	        into_clause from_clause where_clause group_clause  having_clause window_clause # simple_select_select
   	| values_clause # simple_select_values
   	| TABLE relation_expr # simple_select_table
   	/*this replacement solves mutual left-recursive problem betwee simple_select and select_clause */
  
positive.code:  opt_indirection:
                  | opt_indirection indirection_el
  ;
   opt_asymmetric: ASYMMETRIC
                 |
  ;
   opt_target_list: target_list
                  |
  ;
  
negative.code:         //OR	left	logical disjunction
         | a_expr OR a_expr
  
         | a_expr (LESS_LESS|GREATER_GREATER) a_expr
  
         | a_expr qual_op
         | a_expr not_la? IN_P in_expr
  