A Recursive Method to Compute the Layers of a Stratified Graph

摘要

The concept of labeled stratified graph (shortly, stratified graph) was introduced in 10 and developed in 12. Such a structure is a tuple of components uniquely determined by one of them. Among these components, the space L of labels is a subset of a Peano algebra and in 12 a method to construct this set is given. The set L is decomposed in disjoint subsets, which are named layers. In this paper we present a recursive method to obtain these layers, which gives a simple method to construct the set L. Finally we exemplify this method and we show that the case of an infinite set of layers can be encountered.