The calculus of relations has been an important component of the development of logic and
algebra since the middle of the nineteenth century, when Augustus De Morgan observed …

Network segmentation or compartmentalization, and layered protection are two strategies
that are critical in building a secure network. In the literature, layered protection has been …

Network Algebra considers the algebraic study of networks and their behaviour. It contains
general results on the algebraic theory of networks, recent results on the algebraic theory of …

We present an algebraic approach to separation logic. In particular, we give an algebraic
characterisation for assertions of separation logic, discuss different classes of assertions and …

We study the problem of hardening the security of existing networks. Dynamic and static
analysis are two main approaches that are used to address this problem. Dynamic analysis …

We give a formal relation-based definition of scenarios and we show how different scenarios
can be integrated to obtain a more global view of user-system interactions. We restrict …

Echoing Louis Pasteur's quote, we submit the premise that it is advantageous to define
measures of distance between requirements specifications because such measures open …

Using only a simple transition relation one cannot model commands that may or may not
terminate in a given state. In a more general approach commands are relations enriched …

A common approach to dealing with software requirements volatility is to define product
families instead of single products. In earlier papers we have developed an algebra of such …

We first recall the concept of Kleene algebra with domain (KAD). Then we explain how to
use the operators of KAD to define a demonic refinement ordering and demonic operators …