Formal methods have proved their usefulness for an-alyzing the security of protocols. Most existing resultsfocus on trace properties like secrecy or authentication.There are however several security properties, whichcannot be defined (or cannot be naturally defined) astrace properties and require the notion of observationalequivalence. Typical examples are anonymity, pri...

We introduce a specialized ATMS for efficiently computing equivalence relations in multiple contexts. This specialized ATMS overcomes the problems with existing solutions to reasoning with equivalence relations. The most direct implementation of an equivalence relation in the ATMS-encoding the reflexive, transitive and symmetric rules in the consumer architectureproduces redundant equality deri...

Role is a fundamental concept in the analysis of the behavior and function of interacting entities represented by network data. Role discovery is the task of uncovering hidden roles. Node roles are commonly defined in terms of equivalence classes, where two nodes have the same role if they fall within the same equivalence class. Automorphic equivalence, where two nodes are equivalent when they ...

This article extends the Leitmann equivalence method to a class of problems featuring conjugate points. The class is characterised by the requirement that the set of indifference points of a given problem forms a finite stratification.

The inclusion of the space of all knots of a prescribed writhe in a particular isotopy class into the space of all knots in that isotopy class is a weak homotopy equivalence.

We show that the class of Petri nets is less expressive with respect to bisimulation equivalence than the class of PA processes extended with a finite state control unit.

The inclusion of the space of all knots of a prescribed writhe in a particular isotopy class into the space of all knots in that isotopy class is a weak homotopy equivalence.

A central topic in query learning is to determine which classes of Boolean formulas are e ciently learnable with membership and equivalence queries. We consider the class Rk consisting of conjunctions of k unate DNF formulas. This class generalizes the class of k-clause CNF formulas, and the class of unate DNF formulas, both of which are known to be learnable in polynomial time with membership ...

Linear time solv-able optimization problems on certain structured graph families, extended abstract. On the xed parameter complexity of graph enumeration problems deenable in monadic second order logic. in preparartion, 1998. 35 the rst case there is no other vertex z of L such that w and z occur in the same equivalence class of R red , or else z and w are adjacent to both u and v, a contradict...

The Shannon capacity of every induced subgraph of a perfect graph equals its clique number. However, for the co{normal powers of an odd cycle the super{multiplicativity of the clique number makes the determination of capacity one of the hardest problems in combinatorics. We study the asymptotic growth of induced subgraphs of some particular type in powers of a xed graph. In case of a simple gra...