Local one-sided porosity and pretangent spaces.

For subsets of we consider the local right upper porosity and the local right lower porosity as elements of a cluster set of all porosity numbers. The use of a scaling function provides an extension of the concept of porosity numbers on subsets of . The main results describe interconnections between porosity numbers of a set, features of the scaling functions, and the geometry of so-called pretangent spaces to this set. [ABSTRACT FROM AUTHOR]