anchor.diff:      end;
   check_where_clause_is_possible_fold(_, _, {'<',{field,FieldName,_},{const,LtVal}} = F, Acc) ->
       case find_filter_check(FieldName, Acc) of
  +        #filtercheck{'<' = F} ->
  +            %% duplicate < filter
  +            {eliminate, Acc};
           #filtercheck{'=' = {_,_,{const,EqVal}}} when LtVal > EqVal ->
               %% existing equality check is less than than this less than filter,
               %% so this filter is already included so it can be eliminated
  
positive.code:         S?SQL_SELECT.'WHERE'
      ).
  
  
  -endif.
  
negative.code: check_where_clause_is_possible_fold(_, _, {'<=',{field,FieldName,_},{const,LteVal}} = F, Acc) ->
      case find_filter_check(FieldName, Acc) of
          #filtercheck{'<=' = F} ->
              %% duplicate <= filter
              {eliminate, Acc};
          #filtercheck{'=' = {_,_,{const,EqVal}}} when LteVal >= EqVal ->
              %% query like `a = 10 AND a <= 10` the less than or equals can be
  