In this paper we explain how to formalize an “operational” or “state-transition” semantics of a von Neumann programming language in a functional programming language. By adopting an “interpretive” style, one can execute the model in the functional language to “run” programs in the von Neumann language. Given the ability to reason about the functional language, one can use the model to reason ab...

In distributed systems, asynchronous communication is often viewed as a whole whereas there are actually many di erent interaction protocols whose properties are involved in the compatibility of peer compositions. A hierarchy of asynchronous communication models, based on re nements, is established and proven with the TLA Proof System. The work serves as a rst step in the study of the substitua...

Kerberos is designed to allow a user to repeatedly authenticate herself to multiple servers based on a single login. The PKINIT extension to Kerberos modifies the initial round of the protocol to use a PKI instead of long-term shared keys (e.g., password-derived keys). Especially with PKINIT, Kerberos uses a rich collection of cryptographic operations and constructs, and Kerberos, both with and...

We build on the analogy between theorem proving and legal reasoning. In the former case it was shown that mechanized reasoning is always achieved provided there is a theory, a control on this theory and some rules governing this controlled theory once introduced in a given environment. We show that it is possible to identify similar conditions for cognitive systems and also in the legal world. ...

We describe an approach to mechanically prove the correctness of BURS speciications and show how such a tool can be connected with BURS based back-end generators 9]. The proofs are based on the operational semantics of both source and target system languages speciied by means of Abstract State Machines 15]. In 31] we decomposed the correctness condition based on these operational semantics into...