+
+ static Interval_set interval_union (vector<Interval>);
+
+ vector<Interval> const &intervals () const { return intervals_; }
+ vector<Interval>::const_iterator upper_bound (Real x) const;
+ Real nearest_point (Real x, Direction dir = CENTER) const;
+ Interval_set complement () const;
+
+private:
+ vector<Interval> intervals_;