anchor.diff:  	none ->
   	    false;
   	{CoversStart, RemainingIntervals} ->
  -	    if
  -		CoversStart#interval2.last >= Interval#interval2.last ->
  +	    case greater_equals_than(CoversStart#interval2.last, Interval#interval2.last) of
  +		true ->
   		    true;
  -		true ->
  +		false ->
   		    is_covered_helper(intervals:new(CoversStart#interval2.last, Interval#interval2.last), RemainingIntervals)
   	    end
       end.
  
positive.code: 	true -> 
  	    (Begin =< Id) or (Id =< End)
      end.
  
negative.code:     true;
  is_between(_, plus_infinity, plus_infinity) ->
      true;
  is_between(minus_infinity, _, plus_infinity) ->
      true;
  is_between(X, minus_infinity, plus_infinity) ->
      false;
  is_between(X, Y, plus_infinity) ->
      X =< Y;
  is_between(minus_infinity, minus_infinity, _) ->
  