We encountered some limits when using the GreatSPN model checker on life-size models, both in time and space complexity. Even when the exponential blow-up of state space size is adequately handled by the tool thanks to the use of a canonization function that allows to exploit system symmetries, time complexity becomes critical. Indeed the canonization procedure is computationally expensive, and...

translation is an indispensable tool for communication between the diverse linguistic groups. it opens new horizons for the people living in a country so that it makes changes and improvements in their society, especially in the literature. through the translation process, some literary principles and elements are introduced into the home literature which did not exist before. these features em...

We study the time complexity of McKay’s algorithm to compute canonical forms and automorphism groups of graphs. The algorithm is based on a type of backtrack search, and it performs pruning by discovered automorphisms and by hashing partial information of vertex labelings. In practice, the algorithm is implemented in the nauty package. We obtain colorings of Fürer’s graphs that allow the algori...

Over time, process model repositories tend to accumulate duplicate fragments (also called clones) as new process models are created or extended by copying and merging fragments from other models. This phenomenon calls for methods to detect clones in process models, so that these clones can be refactored as separate subprocesses in order to improve maintainability. This paper presents an indexin...

The problem of canonically labeling a graph is studied. Within the general framework of backtracking algorithms based on individualization and refinement, data structures, subroutines, and pruning heuristics especially for fast handling of large and sparse graphs are developed. Experiments indicate that the algorithm implementation in most cases clearly outperforms existing state-of-the-art tools.

In this paper we ask the question What must be added to rst order logic plus least xed point to obtain exactly the polynomial time properties of unordered graphs We consider the languages Lk consisting of rst order logic restricted to k variables and Ck consisting of Lk plus counting quanti ers We give e cient canonization algorithms for graphs characterized by Ck or Lk It follows from known re...