bool operator==(Interval i1, Interval i2) { return i1.l() == i2.l() && i1.r() == i2.r(); }
bool operator>(Interval i1, Interval i2) { if(i1.l() > i2.l()) return true; if(i1.l() < i2.l()) return false; return i1.r() > i2.r(); }