We will review some of the major results in random graphs and some of the more challenging open problems. We will cover algorithmic and structural questions. We will touch on newer models, including those related to the WWW.

Random graphs

https://cmi.ac.in/~madhavan/courses/verification-2011/alur-dill-tcs-94.pdf

A theory of timed automata

The 11th edition of Harrison's Principles of Internal Medicine welcomes Anthony Fauci to its editorial staff, in addition to more than 85 new contributors. While the organization of the book is similar to previous editions, major emphasis has been placed on disorders that affect multiple organ systems. Important advances in genetics, immunology, and oncology are emphasized. Many chapters of the book have been rewritten and describe major advances in internal medicine. Subjects that received only a paragraph or two of attention in previous editions are now covered in entire chapters. Among the chapters that have been extensively revised are the chapters on infections in the compromised host, on skin rashes in infections, on many of the viral infections, including cytomegalovirus and Epstein-Barr virus, on sexually transmitted diseases, on diabetes mellitus, on disorders of bone and mineral metabolism, and on lymphadenopathy and splenomegaly. The major revisions in these chapters and many

Harrison's Principles of Internal Medicine

The concept of an agent has become important in both Artificial Intelligence (AI) and mainstream computer science. Our aim in this paper is to point the reader at what we perceive to be the most important theoretical and practical issues associated with the design and construction of intelligent agents. For convenience, we divide these issues into three areas (though as the reader will see, the divisions are at times somewhat arbitrary). Agent theory is concerned with the question of what an agent is, and the use of mathematical formalisms for representing and reasoning about the properties of agents. Agent architectures can be thought of as software engineering models of agents;researchers in this area are primarily concerned with the problem of designing software or hardware systems that will satisfy the properties specified by agent theorists. Finally, agent languages are software systems for programming and experimenting with agents; these languages may embody principles proposed by theorists. The paper is not intended to serve as a tutorial introduction to all the issues mentioned; we hope instead simply to identify the most important issues, and point to work that elaborates on them. The article includes a short review of current and potential applications of agent technology.

/pdf/intelligent-agents-theory-and-practice-5dchj7p8pc.pdf

Intelligent Agents: Theory and Practice

/pdf/convex-analysisnoer-san-nojin-zhan-nituite-5dl2rbmoyr.pdf

Convex Analysisの二,三の進展について

We consider here Linear Temporal Logic (LTL) formulas interpreted over \emph{finite} traces. We denote this logic by LTLf. The existing approach for LTLf satisfiability checking is based on a reduction to standard LTL satisfiability checking. We describe here a novel direct approach to LTLf satisfiability checking, where we take advantage of the difference in the semantics between LTL and LTLf. While LTL satisfiability checking requires finding a \emph{fair cycle} in an appropriate transition system, here we need to search only for a finite trace. This enables us to introduce specialized heuristics, where we also exploit recent progress in Boolean SAT solving. We have implemented our approach in a prototype tool and experiments show that our approach outperforms existing approaches.

LTLf satisfiability checking

We compare tools for complementing nondeterministic B\"uchi automata with a
recent termination-analysis algorithm. Complementation of B\"uchi automata is a
key step in program verification. Early constructions using a Ramsey-based
argument have been supplanted by rank-based constructions with exponentially
better bounds. In 2001 Lee et al. presented the size-change termination (SCT)
problem, along with both a reduction to B\"uchi automata and a Ramsey-based
algorithm. The Ramsey-based algorithm was presented as a more practical
alternative to the automata-theoretic approach, but strongly resembles the
initial complementation constructions for B\"uchi automata. We prove that the
SCT algorithm is a specialized realization of the Ramsey-based complementation
construction. To do so, we extend the Ramsey-based complementation construction
to provide a containment-testing algorithm. Surprisingly, empirical analysis
suggests that despite the massive gap in worst-case complexity, Ramsey-based
approaches are superior over the domain of SCT problems. Upon further analysis
we discover an interesting property of the problem space that both explains
this result and provides a chance to improve rank-based tools. With these
improvements, we show that theoretical gains in efficiency of the rank-based
approach are mirrored in empirical performance.

/pdf/buchi-complementation-and-size-change-termination-252yqa974s.pdf

Büchi Complementation and Size-Change Termination

Translating formulas of Linear Temporal Logic (ltl) over finite traces, or \({\textsc {ltl}}_f\), to symbolic Deterministic Finite Automata (DFA) plays an important role not only in \({\textsc {ltl}}_f\) synthesis, but also in synthesis for Safety ltl formulas. The translation is enabled by using \(\mathsf {MONA}\), a powerful tool for symbolic, BDD-based, DFA construction from logic specifications. Recent works used a first-order encoding of \({\textsc {ltl}}_f\) formulas to translate \({\textsc {ltl}}_f\) to First Order Logic (fol), which is then fed to \(\mathsf {MONA}\) to get the symbolic DFA. This encoding was shown to perform well, but other encodings have not been studied. Specifically, the natural question of whether second-order encoding, which has significantly simpler quantificational structure, can outperform first-order encoding remained open.

First-Order vs. Second-Order Encodings for \(\textsc {ltl}_f\)-to-Automata Translation

One of the surprising developments in the area of program verification is how ideas introduced by logicians in the early part of the 20th Century ended up yielding by the 21 Century industrial-standard property-specification languages. This development was enabled by the equally unlikely transformation of the mathematical machinery of automata on infinite words, introduced in the early 1960s for second-order logic, into effective algorithms for model-checking tools. This paper attempts to trace the tangled threads of this development.

From Löwenheim to PSL and SVA

We compute the probability of satisfiability of a class of random Horn-SAT formulae, motivated by a connection with the nonemptiness problem of finite tree automata. In particular, when the maximum clause length is three, this model displays a curve in its parameter space along which the probability of satisfiability is discontinuous, ending in a second-order phase transition where it becomes continuous. This is the first case in which a phase transition of this type has been rigorously established for a random constraint satisfaction problem.

Moshe Y. Vardi

Papers

LTLf satisfiability checking

Büchi Complementation and Size-Change Termination

First-Order vs. Second-Order Encodings for \(\textsc {ltl}_f\)-to-Automata Translation

From Löwenheim to PSL and SVA

A continuous-discontinuous second-order transition in the satisfiability of random Horn-SAT formulas