public OrderedSequence <T, V> Insert(T t)
{
var part = Partition(_x.Invariant(t));
return(new OrderedSequence <T, V>(_x, part.Left._finger.Merge(part.Right._finger.PushLeft(new OrderedElement <T, V>(t, _x)))));
}
public override V Measure() => X.Invariant(E);
