anchor.diff:  	true -> 
   	    (Begin =< Id) or (Id =< End)
       end.
  +
  +greater_equals_than(minus_infinity, minus_infinity) ->
  +    true;
  +greater_equals_than(minus_infinity, X) ->
  +    false;
  +greater_equals_than(plus_infinity, plus_infinity) ->
  +    true;
  +greater_equals_than(X, plus_infinity) ->
  +    false;
  +greater_equals_than(X, Y) ->
  +    X >= Y.
  
positive.code:     end.
  
  % @private
  is_covered_helper(#interval2{first=First, last=Last}, _) when First >= Last ->
      true;
  is_covered_helper(Interval, Intervals) ->
      %io:format("helper: ~p ~p~n", [Interval, Intervals]),
      %io:format("find_start: ~p~n", [find_start(Interval#interval2.first, Intervals, [])]),
  
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, _) ->
  