CONTENTS -- Preface -- 1. Böhm's Theorem Stefano Guerrini, Adolfo Piperno and Mariangiola Dezani-Ciancaglini -- 1. Introduction -- 2. Böhm's Theoremfor Trees -- 3. Böhm's Theorem for λ-Calculus -- 4. Follow-Up to Böhm's Theorem. -- 4.1. Böhm's work on Böhm's theorem -- 4.2. Generalizations of Böhm's theorem -- 4.3. Theories and models of λ-calculus -- 4.4. Böhm trees and Böhm-out-technique -- 4.5. Observational equivalence -- References -- 2. Membrane Computing: History and Brief Introduction Gheorghe P˘aun -- 1. Personal Views on the History of Membrane Computing -- 1.1. The pre-history -- 1.2. The first years -- 1.3. The recent years -- 1.4. The next years -- 2. Elements of Membrane Computing -- 2.1. The three main classes of P systems -- 2.2. Cell-like P systems: An informal presentation -- 2.3. Basic ingredients of P systems -- 2.4. A large number of variants -- 2.5. Computational completeness -- 2.6. Computational efficiency -- 2.7. Applications -- References -- 3. Critique of Computational Reason in the Natural Sciences Giuseppe Longo -- 1. Fromthe Alphabet to theMachine -- 2. The Elementary and the Complex -- 3. Imitations and Models -- 3.1. Models, processes, and unpredictability -- 4. Calculus, Physics, and Living Phenomena -- 5. But. . . Natural ProcessesCompute? -- 6. Mnemonic Interlude -- 7. Conclusion: A Question of Principles -- References -- 4. Deterministic Computation with Random G-Networks Erol Gelenbe, Zhi-Hong Mao and Yanda Li -- 1. Introduction -- 2. The GNN and Its Extensions -- 2.1. Stationary or steady-state solution -- 2.2. The bipolar GNN or BGNN -- 3. Approximation of Functions of One Variable by the GNN with a Bounded Number of Layers -- 3.1. Technical premises -- 3.2. BGNN approximation of continuous functions of one variable -- 3.3. CGNN approximation of continuous functions of one variable.

4. Approximation of Continuous Functions of s Variables -- 5. Conclusions -- References -- 5. Assertions: A Personal Perspective Tony Hoare -- 1. Experience in Industry, 1960-1968 -- 2. Research in Belfast, 1968-1977 -- 3. Move to Oxford, 1977-1999 -- 4. Back in Industry, 1999 -- References -- 6. The Call To ARMs Steve Furber -- 1. Acorn Computer Ltd -- 2. The BBCMicro -- 3. Why Design aMicroprocessor?. -- 4. The ARMDesign Process -- 5. The Formation of ARM Ltd -- 6. A 20-year Perspective -- References -- 7. Carl Adam Petri and "Petri Nets" Wilfried Brauer and Wolfgang Reisig -- 1. Introduction -- 2. The Dissertation -- 3. Carl Adam Petri, The Man -- 4. The Years Until 1980 -- 5. The Years Since 1980 -- 6. Honors -- 7. WhatWill the Future Bring? -- References -- 8. From Stochastic Modeling to Operational Analysis: The Journey Begins Je.rey P. Buzen -- 1. Stochastic Processes and the Central Server Model -- 2. Early Concerns About Stochastic Modeling -- 3. Impact of Empirical Success -- 4. Lectures at Serre Chevalier and Bologna -- 5. Emergence of Operational Analysis -- References -- 9. From Rocket Control to Virtual Design Olivier Pironneau -- 1. Computational Fluid Dynamics -- 2. Open Problems -- 3. Computational Fluid Dynamics and Computer Science -- References.