+
+ Real linear_combination (Real x) const;
+ string to_string () const;
+
+ bool contains (T r) const;
+ void negate ()
+ {
+ T r = -at (LEFT);
+ T l = -at (RIGHT);
+ at (LEFT) = l;
+ at (RIGHT) = r;
+ }
+
+ void swap ()
+ {
+ T t = at (LEFT);
+ at (LEFT) = at (RIGHT);
+ at (RIGHT) = t;
+ }
+
+ static bool left_less (Interval_t<T> const &a, Interval_t<T> const &b)
+ {
+ return a[LEFT] < b[RIGHT];
+ }