This volume is exemplary in showing how the shared interests of three different areas of research can lead to significant cooperation and fruitful exchanges of techniques. Six papers each present in an accessible way an exciting contribution to the study and use of algebras, diagrams and decisions. These themes are of interest to researchers in the areas of language, logic and computation.

The types of contributions range from indispensable overview papers about shared formal methods to inspirational applications of formal tools to specific problems.

Contributors to this volume are Pieter Adriaans, Sergei Artemov, Steven Givant, Edward Keenan, Almerindo Ojeda, Patrick Scotto di Luzio, and Edward Stabler.

Kees Vermeulen is a researcher at CWI, the National Research Center for Mathematics and Computer Science in Amsterdam, The Netherlands. Ann Copestake is a lecturer in the University of Cambridge Computer Laboratory, United Kingdom.

- Contributors vi
- Preface vii
- 1 Syntactic Invariants 1

Edward L. Keenan and Edward P. Stabler
- 2 The Plurality of Plurals 37

Almerindo E. Ojeda
- 3 Decision Problems on the Calculus of Relations 67

Steven Givant
- 4 Unified Semantics for Modality and Lambda-terms via Proof Polynomials 89

Sergei N. Artemov
- 5 Patching Up a Logic of Venn Diagrams 119

Patrick Scotto Di Luzio
- 6 Learning Shallow Context-Free Languages Under Simple Distributions 135

Pieter W. Adriaans
- Index 169

8/30/2002