CSE 625: Computer Aided Verification, Spring 2003
(Listed as Asynchronous Systems)
Class:TueThu 2:20pm
 3:40pm, Melville Library room N4006
Office hours: TueThu 45pm, CS Building room
1425, and by appointment
Motivation
Reactive systems are becoming an integral part of nearly every engineered
product: they control consumer products, commercial aircraft, nuclear power
plants, medical devices, weapon systems, aerospace systems, automobiles,
public transportation systems, and so on. At the same time quality
and confidence issues are increasing in importance. Errors may result in
loss of life, destruction of property, failure of businesses, and environmental
harm. Today, designers check that a reactive system works properly
by using simulation and testing. However, as reactive systems become more
complex
and pervasive, these traditional techniques are not sufficient to assure
desired reliability. Model checking and related computeraided verification
techniques are emerging as practical alternatives. They allow the designer
to verify that a mathematical model of a system satisfies its abstract
logical specification. This approach has been most effective for controlintensive
components, and is rapidly becoming an integral part of the design cycle
in many companies.
Objectives
The participants will learn how to model a reactive
(hardware or software) sytem, express desired properties of the reactive
system and check that the system satisfies these properties. They will
get familiar with the algorithmic methods used for this check.
Prerequisites
The course requires basic knowledge of algorithms, data structures, automata
theory, computational complexity, and propositional logic. Knowledge of
operating systems, communication protocols, and hardware is useful. The
course requires mathematical maturity, and is appropriate for graduate
students who wish to pursue research in formal methods or related areas.
If you need more information to decide, contact the instructor.
Overview
The course introduces the theory and practice of formal methods for the
design and analysis of concurrent and embedded systems. The emphasis is
on the underlying logical and automatatheoretic concepts, the algorithmic
solutions, and heuristics to cope with the high computational complexity.
Topics include

Models of reactive systems: states and events, nondeterminism and
concurrency, synchrony and asynchrony, realtime and hybrid systems, open
systems.

Properties of reactive sytems: safety and liveness, linear and branching
temporal logic, refinement preorders.

Verification algorithms: temporal logic model checking, theory of
omega automata, realizability and control, minimization.

Verification techniques: symbolic model checking, onthefly model
checking, state space reduction methods, compositional and hierarchical
reasoning, abstract interpretation.
Software
We will use the model checker MOCHA
being currently developed at Stony Brook, UPenn and UC Berkeley.
Related tools include
Reading
The course will use the draft of a forthcoming textbook titled Computeraided
verification by R. Alur & T. Henzinger. Chapters will be posted
on the web as needed.
Following books are recommended for additional reading

Model Checking, E.M. Clarke, O. Grumberg and D.A. Peled. MIT Press. 2000

Design
and Validation of Computer Protocols, G.J. Holzmann. PrenticeHall, 1991

Symbolic model checking: an approach to the state explosion problem, K.L.
McMillan, Kluwer Academic Publishers, 1993

The temporal logic of reactive and concurrent systems: Specification, Z.
Manna and A. Pnueli, SpringerVerlag, 1991
Grading
There will be periodic homework assignments consisting of problems and
experimentation with MOCHA.
There will be no exams.
There will be a class project. The project can be done in groups
of two or three, and will require a presentation in the final week. Projects
can be of various forms:

Programming: Implementation of algorithms in the programming environment
MOCHA

Case study: Modeling, specification, and analysis of an application design

Tool Comparison: Using different model checkers to model and analyze the
same design to understand differences between various approaches

Surveys: Read a few papers on a related topic not covered in the class

Theory: Exploratory research
Tentative Schedule
0 Introduction
1/25:Introduction
1
Modeling Lanuage Reactive Modules
1/28, 1/30: Definition, operations on reactive modules, examples
2
Invariant verification
2/4,6: Transition graphs, invariants, graph traversal, state explosion,
compositional reasoning
3
Symbolic Graph Search
2/11,13: Symbolic invariant verification, binary decision diagrams
BDDs
4
Graph Minimization
2/18,20: Graph partitions, partition refinement, reachable partition refinement
5
Temporal Safety Requirements
2/25: State logics, safe temporal logic STL
2/27: STL model checking, distinguishing and expressive power
6
Automatatheoretic Safety Verification
3/4: Automata, safe automata logic SAL, operations on automata, model checking7:
Hierarchical Verification
7
Hierarchical Verification
3/6: Trace semantics, compositionality, asssumeguarantee
3/11: Simulation relations, homomorphisms
8
Fair Modules
3/13: Omegalanguages, safety versus liveness
3/25: Fairness, fair modules, examples
9
Response Verification
3/27: Searching for fair cycles and response verification
10
Temporal Liveness Requirements
4/1: CTL, Mucalculus, and Symbolic model checking
11
Automatatheoretic Liveness Verification
4/3: Theory of omegaregular languages
12
Linear Temporal Logic
4/8: Linear temporal logic LTL
4/10,15: MSCs, hierarchical modules, and UML
Week of 5/1: Project presentations
Last updated on Feb 4, 2003 by Radu
Grosu