AVL-trees for localized search

We present a data structure based on AVL-trees which allows an insertion or a deletion to be performed in time O(log d), where d is the distance of the position searched for from a finger which points to the end of the file. Moving a finger to a distance d costs O(log d). This result demonstrates the power of the oldest basic data structure, the AVL-tree. A special case of interest is an efficient implementation of searchable priority queues such that Deletemin requires only constant time