Chrystopher L. Nehaniv

Katrin S. Lohan, Katharina J. Rohlfing, Karola Pitsch, Joe Saunders, Hagen Lehmann, Chrystopher L. Nehaniv, Kerstin Fischer, Britta Wrede: Tutor Spotter: Proposing a Feature Set and Evaluating It in a Robotic System. I. J. Social Robotics 4(2): 131-146 (2012)

Paolo Dini, Chrystopher L. Nehaniv, Attila Egri-Nagy, Maria J. Schilstra, Daniel Schreckling, Joachim Posegga, Gábor Horváth, Alastair J. Munro: BIOMICS Project: Biological and Mathematical Basis of Interaction Computing. IJUC 8(4): 283-287 (2012)

Philippe Capdepuy, Daniel Polani, Chrystopher L. Nehaniv: Perception-action loops of multiple agents: informational aspects and the impact of coordination. Theory in Biosciences 131(3): 149-159 (2012)

Katrin Solveig Lohan, Katharina J. Rohlfing, Joe Saunders, Chrystopher L. Nehaniv, Britta Wrede: Contingency scaffolds language learning. ICDL-EPIROB 2012: 1-6

Joe Saunders, Hagen Lehmann, Frank Förster, Chrystopher L. Nehaniv: Robot acquisition of lexical meaning - moving towards the two-word stage. ICDL-EPIROB 2012: 1-7

Esther-Anna Loeliger, Chrystopher L. Nehaniv, Alastair J. Munro: Heat-Maps and Visualization for Heterogeneous Biomedical Data Based on Information Distance Geometry. IPCAT 2012: 183-187

Paolo Dini, Chrystopher L. Nehaniv, Attila Egri-Nagy, Maria J. Schilstra: Algebraic Analysis of the Computation in the Belousov-Zhabotinksy Reaction. IPCAT 2012: 216-224

Frank Broz, Hagen Lehmann, Chrystopher L. Nehaniv, Kerstin Dautenhahn: Mutual gaze, personality, and familiarity: Dual eye-tracking during conversation. RO-MAN 2012: 858-864

Karola Pitsch, Katrin S. Lohan, Katharina J. Rohlfing, Joe Saunders, Chrystopher L. Nehaniv, Britta Wrede: Better be reactive at the beginning. Implications of the first seconds of an encounter for the tutoring style in human-robot-interaction. RO-MAN 2012: 974-981

Frank Broz, Chrystopher L. Nehaniv, Hatice Kose-Bagci, Kerstin Dautenhahn: Interaction Histories and Short Term Memory: Enactive Development of Turn-taking Behaviors in a Childlike Humanoid Robot. CoRR abs/1202.5600 (2012)

Attila Egri-Nagy, James D. Mitchell, Chrystopher L. Nehaniv: Algorithms for the Efficient Calculation of the Holonomy Decomposition. AFL 2011: 389-390

Attila Egri-Nagy, Chrystopher L. Nehaniv: Symmetries of Automata. AFL 2011: 391

Esther-Anna Loeliger, Chrystopher L. Nehaniv: Affordance Graphs for User Interface Design: Application of Category-theoretic Constructs. AFL 2011: 392-394

Attila Egri-Nagy, Brigitte Galliot, Felix Naef, Chrystopher L. Nehaniv: Information processing in cells and tissues (IPCAT'2009): From small scale dynamics to understanding systems behavior. Biosystems 102(1): 1-2 (2010)

Maria J. Schilstra, Chrystopher L. Nehaniv: Stochastic model of template-directed elongation processes in biology. Biosystems 102(1): 55-60 (2010)

Hatice Kose-Bagci, Kerstin Dautenhahn, Dag Sverre Syrdal, Chrystopher L. Nehaniv: Drum-mate: interaction dynamics and gestures in human-humanoid drumming experiments. Connect. Sci. 22(2): 103-134 (2010)

Caroline Lyon, Yo Sato, Joe Saunders, Chrystopher L. Nehaniv: Correction to "What Is Needed for a Robot to Acquire Grammar? Some Underlying Primitive Mechanisms for the Synthesis of Linguistic Ability" [Oct 09 187-195]. IEEE T. Autonomous Mental Development 2(2): 144 (2010)

Angelo Cangelosi, Giorgio Metta, Gerhard Sagerer, Stefano Nolfi, Chrystopher L. Nehaniv, Kerstin Fischer, Jun Tani, Tony Belpaeme, Giulio Sandini, Francesco Nori, Luciano Fadiga, Britta Wrede, Katharina J. Rohlfing, Elio Tuci, Kerstin Dautenhahn, Joe Saunders, Arne Zeschel: Integration of Action and Language Knowledge: A Roadmap for Developmental Robotics. IEEE T. Autonomous Mental Development 2(3): 167-195 (2010)

Frank Förster, Chrystopher L. Nehaniv: Representations of Time in Symbol Grounding Systems. AAAI Spring Symposium: It's All in the Timing 2010

Hatice Kose-Bagci, Frank Broz, Qiming Shen, Kerstin Dautenhahn, Chrystopher L. Nehaniv: As Time Goes By: Representing and Reasoning About Timing in Human-Robot Interaction Studies. AAAI Spring Symposium: It's All in the Timing 2010

Attila Egri-Nagy, Paolo Dini, Chrystopher L. Nehaniv, Maria J. Schilstra: Transformation Semigroups as Constructive Dynamical Spaces. OPAALS 2010: 245-265

Attila Egri-Nagy, Chrystopher L. Nehaniv: On Straight Words and Minimal Permutators in Finite Transformation Semigroups. CIAA 2010: 115-124

Moritz Buck, Chrystopher L. Nehaniv: Looking for Evidence of Differentiation and Cooperation: Natural Measures for the Study of Evolution of Multicellularity. Advances in Complex Systems 12(3): 255-271 (2009)

Hatice Kose-Bagci, Ester Ferrari, Kerstin Dautenhahn, Dag Sverre Syrdal, Chrystopher L. Nehaniv: Effects of Embodiment and Gestures on Social Interaction in Drumming Games with a Humanoid Robot. Advanced Robotics 23(14): 1951-1996 (2009)

Caroline Lyon, Yo Sato, Joe Saunders, Chrystopher L. Nehaniv: What is Needed for a Robot to Acquire Grammar? Some Underlying Primitive Mechanisms for the Synthesis of Linguistic Ability. IEEE T. Autonomous Mental Development 1(3): 187-195 (2009)

Hatice Kose-Bagci, Kerstin Dautenhahn, Chrystopher L. Nehaniv: Drumming with a Humanoid Robot: Lessons Learnt from Designing and Analysing Human-Robot Interaction Studies. AAAI Spring Symposium: Experimental Design for Real-World Systems 2009: 25-32

Frank Förster, Chrystopher L. Nehaniv, Joe Saunders: Robots That Say 'No'. ECAL (2) 2009: 158-166

Tom Anthony, Daniel Polani, Chrystopher L. Nehaniv: Impoverished Empowerment: 'Meaningful' Action Sequence Generation through Bandwidth Limitation. ECAL (2) 2009: 294-301

Sander G. van Dijk, Daniel Polani, Chrystopher L. Nehaniv: Hierarchical Behaviours: Getting the Most Bang for Your Bit. ECAL (2) 2009: 342-349

Attila Egri-Nagy, Chrystopher L. Nehaniv: Computational Understanding and Manipulation of Symmetries. CoRR abs/0908.3091 (2009)

Maria J. Schilstra, Chrystopher L. Nehaniv: Bio-Logic: Gene Expression and the Laws of Combinatorial Logic. Artificial Life 14(1): 121-133 (2008)

Johannes F. Knabe, Chrystopher L. Nehaniv, Maria J. Schilstra: Genetic Regulatory Network Models of Biological Clocks: Evolutionary History Matters. Artificial Life 14(1): 135-148 (2008)

Attila Egri-Nagy, Chrystopher L. Nehaniv: Hierarchical Coordinate Systems for Understanding Complexity and its Evolution, with Applications to Genetic Regulatory Networks. Artificial Life 14(3): 299-312 (2008)

Rene te Boekhorst, Irina I. Abnizova, Chrystopher L. Nehaniv: Discriminating coding, non-coding and regulatory regions using rescaled range and detrended fluctuation analysis. Biosystems 91(1): 183-194 (2008)

Moritz Buck, Chrystopher L. Nehaniv: Communication and complexity in a GRN-based multicellular system for graph colouring. Biosystems 94(1-2): 28-33 (2008)

Johannes F. Knabe, Chrystopher L. Nehaniv, Maria J. Schilstra: Do motifs reflect evolved function? - No convergent evolution of genetic regulatory network subgraph topologies. Biosystems 94(1-2): 68-74 (2008)

Attila Egri-Nagy, Chrystopher L. Nehaniv, John L. Rhodes, Maria J. Schilstra: Automatic analysis of computation in biochemical reactions. Biosystems 94(1-2): 126-134 (2008)

Attila Egri-Nagy, Chrystopher L. Nehaniv: Algebraic properties of automata associated to Petri nets and applications to computation in biological systems. Biosystems 94(1-2): 135-144 (2008)

Wan Ching Ho, Kerstin Dautenhahn, Chrystopher L. Nehaniv: Computational memory architectures for autobiographic agents interacting in a complex virtual environment: a working model. Connect. Sci. 20(1): 21-65 (2008)

Nuno Otero, Joe Saunders, Kerstin Dautenhahn, Chrystopher L. Nehaniv: Teaching robot companions: the role of scaffolding and event structuring. Connect. Sci. 20(2&3): 111-134 (2008)

Paul Wernick, Tracy Hall, Chrystopher L. Nehaniv: Software evolutionary dynamics modelled as the activity of an actor-network. IET Software 2(4): 321-336 (2008)

Gábor Horváth, Chrystopher L. Nehaniv, Csaba Szabó: An assertion concerning functionally complete algebras and NP-completeness. Theor. Comput. Sci. 407(1-3): 591-595 (2008)

Philippe Capdepuy, Daniel Polani, Chrystopher L. Nehaniv: Adaptation of the Perception-Action Loop Using Active Channel Sampling. AHS 2008: 443-450

Johannes F. Knabe, Chrystopher L. Nehaniv, Maria J. Schilstra: Regulation of gene regulation - smooth binding with dynamic affinity affects evolvability. IEEE Congress on Evolutionary Computation 2008: 890-896

Ben Robins, Kerstin Dautenhahn, Rene te Boekhorst, Chrystopher L. Nehaniv: Behaviour delay and robot expressiveness in child-robot interactions: a user study on interaction kinesics. HRI 2008: 17-24

Nuno Otero, Aris Alissandrakis, Kerstin Dautenhahn, Chrystopher L. Nehaniv, Dag Sverre Syrdal, Kheng Lee Koay: Human to robot demonstrations of routine home tasks: exploring the role of the robot's feedback. HRI 2008: 177-184

Naeem Assif Mirza, Chrystopher L. Nehaniv, Kerstin Dautenhahn, Rene te Boekhorst: Developing social action capabilities in a humanoid robot using an interaction history architecture. Humanoids 2008: 609-616

Hatice Kose-Bagci, Kerstin Dautenhahn, Chrystopher L. Nehaniv: Emergent dynamics of turn-taking interaction in drumming games with a humanoid robot. RO-MAN 2008: 346-353

Alexander S. Klyubin, Daniel Polani, Chrystopher L. Nehaniv: Representations of Space and Time in the Maximization of Information Flow in the Perception-Action Loop. Neural Computation 19(9): 2387-2432 (2007)

Aris Alissandrakis, Chrystopher L. Nehaniv, Kerstin Dautenhahn: Correspondence Mapping Induced State and Action Metrics for Robotic Imitation. IEEE Transactions on Systems, Man, and Cybernetics, Part B 37(2): 299-307 (2007)

Megan Davis, Kerstin Dautenhahn, Chrystopher L. Nehaniv, Stuart D. Powell: The narrative construction of our (social) world: steps towards an interactive learning environment for children with autism. Universal Access in the Information Society 6(2): 145-157 (2007)

Philippe Capdepuy, Daniel Polani, Chrystopher L. Nehaniv: Grounding Action-Selection in Event-Based Anticipation. ECAL 2007: 253-262

Philippe Capdepuy, Daniel Polani, Chrystopher L. Nehaniv: Constructing the Basic Umwelt of Artificial Agents: An Information-Theoretic Approach. ECAL 2007: 375-383

Hatice Kose-Bagci, Kerstin Dautenhahn, Dag Sverre Syrdal, Chrystopher L. Nehaniv: Drum-mate: A human-humanoid drumming experience. Humanoids 2007: 242-247

Joe Saunders, Nuno Otero, Chrystopher L. Nehaniv: Issues in Human/Robot Task Structuring and Teaching. RO-MAN 2007: 708-713

Attila Egri-Nagy, Chrystopher L. Nehaniv: Cycle Structure in Automata and the Holonomy Decomposition. Acta Cybern. 17(2) (2006)

Lars Olsson, Chrystopher L. Nehaniv, Daniel Polani: From unknown sensors and actuators to actions grounded in sensorimotor perceptions. Connect. Sci. 18(2): 121-144 (2006)

Chrystopher L. Nehaniv, Naeem Assif Mirza, Lars Olsson: Development Via Information Self-structuring of Sensorimotor Experience and Interaction. 50 Years of Artificial Intelligence 2006: 87-98

Joe Saunders, Chrystopher L. Nehaniv, Kerstin Dautenhahn: Teaching robots by moulding behavior and scaffolding the environment. HRI 2006: 118-125

Aris Alissandrakis, Chrystopher L. Nehaniv, Kerstin Dautenhahn, Joe Saunders: Evaluation of robot imitation attempts: comparison of the system's and the human's perspectives. HRI 2006: 134-141

Kerstin Dautenhahn, Michael L. Walters, Sarah Woods, Kheng Lee Koay, Chrystopher L. Nehaniv, Emrah Akin Sisbot, Rachid Alami, Thierry Siméon: How may I serve you?: a robot companion approaching a seated person in a helping context. HRI 2006: 172-179

Mike Blow, Kerstin Dautenhahn, Andrew Appleby, Chrystopher L. Nehaniv, David Lee: The art of designing robot faces: dimensions for human-robot interaction. HRI 2006: 331-332

Megan Davis, Kerstin Dautenhahn, Chrystopher L. Nehaniv, Stuart D. Powell: TouchStory: Towards an Interactive Learning Environment for Helping Children with Autism to Understand Narrative. ICCHP 2006: 785-792

Attila Egri-Nagy, Chrystopher L. Nehaniv: Making Sense of the Sensory Data - Coordinate Systems by Hierarchical Decomposition. KES (3) 2006: 333-340

Philippe Capdepuy, Daniel Polani, Chrystopher L. Nehaniv: Construction of an Internal Predictive Model by Event Anticipation. SAB ABiALS 2006: 218-232

Paul Vogt, Yuuga Sugita, Elio Tuci, Chrystopher L. Nehaniv (Eds.): Symbol Grounding and Beyond, Third International Workshop on the Emergence and Evolution of Linguistic Communication, EELC 2006, Rome, Italy, September 30 - October 1, 2006, Proceedings. Lecture Notes in Computer Science 4211, Springer 2006, isbn 3-540-45769-0

Chrystopher L. Nehaniv, Naeem Assif Mirza, Kerstin Dautenhahn, I. René J. A. te Boekhorst: Extending the Temporal Horizon of Autonomous Robots. AMiRE 2005: 389-395

Alexander S. Klyubin, Daniel Polani, Chrystopher L. Nehaniv: Empowerment: a universal agent-centric measure of control. Congress on Evolutionary Computation 2005: 128-135

Chrystopher L. Nehaniv: Sensorimotor experience and its metrics: informational geometry and the temporal horizon. Congress on Evolutionary Computation 2005: 142-149

Naeem Assif Mirza, Chrystopher L. Nehaniv, Kerstin Dautenhahn, I. René J. A. te Boekhorst: Using temporal information distance to locate sensorimotor experience in a metric space. Congress on Evolutionary Computation 2005: 150-157

Robert Lowe, Chrystopher L. Nehaniv, Daniel Polani, Lola Cañamero: The degree of potential damage in agonistic contests and its effects on social aggression, territoriality and display evolution. Congress on Evolutionary Computation 2005: 351-358

Wan Ching Ho, Orlando Avila-García, Chrystopher L. Nehaniv: Assessing the performance of different behavior selection architectures in a large and complex virtual environment. Congress on Evolutionary Computation 2005: 359-365

Wan Ching Ho, Kerstin Dautenhahn, Chrystopher L. Nehaniv: Autobiographic agents in dynamic virtual environments - performance comparison for different memory control architectures. Congress on Evolutionary Computation 2005: 573-580

Rene te Boekhorst, Michael L. Walters, Kheng Lee Koay, Kerstin Dautenhahn, Chrystopher L. Nehaniv: A study of a single robot interacting with groups of children in a rotation game scenario. CIRA 2005: 35-40

Aris Alissandrakis, Chrystopher L. Nehaniv, Kerstin Dautenhahn, Joe Saunders: An Approach for Programming Robots by Demonstration: Generalization Across Different Initial Configurations of Manipulated Objects. CIRA 2005: 61-66

David Jacob, Daniel Polani, Chrystopher L. Nehaniv: Legs that can walk: embodiment-based modular reinforcement learning applied. CIRA 2005: 365-372

David Jacob, Daniel Polani, Chrystopher L. Nehaniv: Faster learning in embodied systems through characteristic attitudes. CIRA 2005: 573-579

Naeem Assif Mirza, Chrystopher L. Nehaniv, Kerstin Dautenhahn, Rene te Boekhorst: Using sensory-motor phase-plots to characterise robot-environment interactions. CIRA 2005: 581-586

Lars Olsson, Chrystopher L. Nehaniv, Daniel Polani: Sensor adaptation and development in robots by entropy maximization of sensory data. CIRA 2005: 587-592

Alexander S. Klyubin, Daniel Polani, Chrystopher L. Nehaniv: All Else Being Equal Be Empowered. ECAL 2005: 744-753

Michael L. Walters, Kerstin Dautenhahn, Kheng Lee Koay, Christina Kaouri, Rene te Boekhorst, Chrystopher L. Nehaniv, Iain Werry, David Lee: Close encounters: spatial distances between people and a robot of mechanistic appearance. Humanoids 2005: 450-455

Chrystopher L. Nehaniv: Self-replication, Evolvability and Asynchronicity in Stochastic Worlds. SAGA 2005: 126-169

Chrystopher L. Nehaniv: Asynchronous Automata Networks Can Emulate any Synchronous Automata Network. IJAC 14(5-6): 719-739 (2004)

Lars Olsson, Chrystopher L. Nehaniv, Daniel Polani: Sensory Channel Grouping and Structure from Uninterpreted Sensor Data. Evolvable Hardware 2004: 153-160

Alexander S. Klyubin, Daniel Polani, Chrystopher L. Nehaniv: Organization of the Information Flow in the Perception-Action Loop of Evolved Agents. Evolvable Hardware 2004: 177-

Caroline Lyon, Chrystopher L. Nehaniv, Sandra Warren, Bob Dickerson, Jean Baillie: Homophony and Disambiguation Through Sequential Processes in the Evolution of Language. JSAI Workshops 2004: 315-324

Jean Baillie, Chrystopher L. Nehaniv, Patrick Quick, Attila Egri-Nagy, Sandra Warren: Mirroring, Deixis, and Interaction Topology in the Emergence of Shared Vocabularies. JSAI Workshops 2004: 325-334

Attila Egri-Nagy, Chrystopher L. Nehaniv: Algebraic Hierarchical Decomposition of Finite State Automata: Comparison of Implementations for Krohn-Rhodes Theory. CIAA 2004: 315-316

Pál Dömösi, Chrystopher L. Nehaniv, John L. Rhodes: Finite semigroups, feedback, and the Letichevsky criteria on non-empty words in finite automata. Theor. Comput. Sci. 302(1-3): 295-317 (2003)

Attila Egri-Nagy, Chrystopher L. Nehaniv: Evolvability of the Genotype-Phenotype Relation in Populations of Self-Replicating Digital Organisms in a Tierra-Like System. ECAL 2003: 238-247

Tom Quick, Chrystopher L. Nehaniv, Kerstin Dautenhahn, Graham Roberts: Evolving Embodied Genetic Regulatory Network-Driven Control Systems. ECAL 2003: 266-277

Chrystopher L. Nehaniv, Kerstin Dautenhahn, Adam Lee Newton: The Robot in the Swarm: An Investigation into Agent Embodiment within Virtual Robotic Swarms. ECAL 2003: 829-838

Wan Ching Ho, Kerstin Dautenhahn, Chrystopher L. Nehaniv: Comparing Different Control Architectures for Autobiographic Agents in Static Virtual Environments. IVA 2003: 182-191

Gillian Z. Elston, Chrystopher L. Nehaniv: Holonomy Embedding of Arbitrary Stable Semigroups. IJAC 12(6): 791-810 (2002)

Aris Alissandrakis, Chrystopher L. Nehaniv, Kerstin Dautenhahn: Imitation with ALICE: learning to imitate corresponding actions across dissimilar embodiments. IEEE Transactions on Systems, Man, and Cybernetics, Part A 32(4): 482-496 (2002)

Chrystopher L. Nehaniv: Self-Reproduction in Asynchronous Cellular Automata. Evolvable Hardware 2002: 201-209

Chrystopher L. Nehaniv, Kerstin Dautenhahn: Imitation in Natural and Artificial Systems. Cybernetics and Systems 32(1): 1-10 (2001)

Chrystopher L. Nehaniv, Kerstin Dautenhahn: Like Me?- Measures of Correspondence and Imitation. Cybernetics and Systems 32(1): 11-51 (2001)

Martin Loomes, Chrystopher L. Nehaniv: Fact and Artifact: Reification and Drift in the History and Growth of Interactive Software Systems. Cognitive Technology 2001: 25-39

Alan F. Blackwell, Carol Britton, Anna Louise Cox, Thomas R. G. Green, Corin A. Gurr, Gada F. Kadoda, Maria Kutar, Martin Loomes, Chrystopher L. Nehaniv, Marian Petre, Chris Roast, Chris Roe, Allan Wong, R. Michael Young: Cognitive Dimensions of Notations: Design Tools for Cognitive Technology. Cognitive Technology 2001: 325-341

Maria Kutar, Chrystopher L. Nehaniv, Carol Britton, Sara Jones: The Cognitive Dimensions of an Artifact vis-à-vis Individual Human Users: Studies with Notations for the Temporal Specification of Interactive Systems. Cognitive Technology 2001: 342-355

Meurig Beynon, Chrystopher L. Nehaniv, Kerstin Dautenhahn (Eds.): Cognitive Technology: Instruments of Mind, 4th International Conference, CT 2001, Warwick, UK, August 6-9, 2001, Proceedings. Lecture Notes in Computer Science 2117, Springer 2001, isbn 3-540-42406-7

Chrystopher L. Nehaniv, Günter P. Wagner: The Right Stuff: Appropriate Mathematics for Evolutionary and Developmental Biology . Artificial Life 6(1): 1-2 (2000)

Chrystopher L. Nehaniv, John L. Rhodes: The Evolution and Understanding of Hierarchical Compleixity in Biology from an Algebraic Perspective. Artificial Life 6(1): 45-67 (2000)

Masami Ito, Chrystopher L. Nehaniv: Semigroups and Algebraic Engineering - Foreword. Theor. Comput. Sci. 245(1): 1 (2000)

Pál Dömösi, Chrystopher L. Nehaniv: On complete systems of automata. Theor. Comput. Sci. 245(1): 27-54 (2000)

Maria Kutar, Carol Britton, Chrystopher L. Nehaniv: Specifying Multiple Time Granularities in Interactive Systems. DSV-IS 2000: 51-63

Chrystopher L. Nehaniv: Computation for Metaphors, Analogy, and Agents. Lecture Notes in Computer Science 1562, Springer 1999, isbn 3-540-65959-5

Pál Dömösi, Chrystopher L. Nehaniv: Complete Finite Automata Network Graphs with Minimal Number of Edges. Acta Cybern. 14(1): 37-50 (1999)

Chrystopher L. Nehaniv: Review of Mathematical Support for Molecular Biology edited by Martin Farach-Colton , Fred S. Roberts, Martin Vingron, and Michael Waterman. SIGACT News 30(4): 4-7 (1999)

Tom Quick, Kerstin Dautenhahn, Chrystopher L. Nehaniv, Graham Roberts: On Bots and Bacteria: Ontology Independent Embodiment. ECAL 1999: 339-343

Lothar M. Schmitt, Chrystopher L. Nehaniv, Robert H. Fujii: Linear Analysis of Genetic Algorithms. Theor. Comput. Sci. 200(1-2): 101-134 (1998)

Wah Kheang Cheung, Chrystopher L. Nehaniv, Kenjiro Takai Miura, Yin Seong Ho: Hierarchical Multimodel-Based Structural Consistency Support Tools for Specifying and Prototyping Complex Systems. COMPSAC 1995: 245-254