Unify and Merge in Fluid Construction Grammar

  • Luc Steels
  • Joachim De Beule
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4211)


Research into the evolution of grammar requires that we employ formalisms and processing mechanisms that are powerful enough to handle features found in human natural languages. But the formalism needs to have some additional properties compared to those used in other linguistics research that are specifically relevant for handling the emergence and progressive co-ordination of grammars in a population of agents. This document introduces Fluid Construction Grammar, a formalism with associated parsing, production, and learning processes designed for language evolution research. The present paper focuses on a formal definition of the unification and merging algorithms used in Fluid Construction Grammar. The complexity and soundness of the algorithms and their relation to unification in logic programming and other unification-based grammar formalisms are discussed.


Simple Expression Special Operator Syntactic Structure Semantic Category Semantic Structure 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. 1.
    Batali, J.: The negotiation and acquisition of recursive grammars as a result of competition among exemplars. In: Briscoe, T. (ed.) Linguistic Evolution through Language Acquisition: Formal and Computational Models. Cambridge University Press, Cambridge (2002)Google Scholar
  2. 2.
    Bergen, B.K., Chang, N.C.: Embodied Construction Grammar in Simulation-Based Language Understanding. In: Ostman, J.O., Fried, M. (eds.) Construction Grammar(s): Cognitive and Cross-Language Dimensions. John Benjamins Publishing Company, Amsterdam (2003)Google Scholar
  3. 3.
    Briscoe, T. (ed.): Linguistic Evolution through Language Acquisition: Formal and Computational Models. Cambridge University Press, Cambridge (2002)Google Scholar
  4. 4.
    Cangelosi, A., Parisi, D. (eds.): Simulating the Evolution of Language. Springer, Berlin (2001)Google Scholar
  5. 5.
    Chomsky, N.: Logical Structure of Linguistic Theory. Plenum (1955)Google Scholar
  6. 6.
    Croft, W.A.: Radical Construction Grammar; Syntactic Theory in Typological Perspective. Oxford University Press, Oxford (2001)Google Scholar
  7. 7.
    De Beule, J., Bergen, B.: On the emergence of compositionality. In: Accepted for the Sixth Evolution of Language Conference, Rome (2006)Google Scholar
  8. 8.
    De Beule, J., Steels, L.: Hierarchy in Fluid Construction Grammars. In: Furbach, U. (ed.) KI 2005. LNCS, vol. 3698, pp. 1–15. Springer, Heidelberg (2005)CrossRefGoogle Scholar
  9. 9.
    Degyarev, A., Voronkov, A.: Equality Elimination for Semantic Tableaux. Tech. report 90, Computer Science department, Uppsala University, Upsalla, Sweden (1994)Google Scholar
  10. 10.
    Dovier, A., Pontelli, E., Rossi, G.: Set Unification. arXiv:cs.LO/0110023v1 (2001)Google Scholar
  11. 11.
    Goldberg, A.E.: Constructions: A construction grammar approach to argument structure. University of Chicago Press, Chicago (1995)Google Scholar
  12. 12.
    Hashimoto, T., Ikegami, T.: Emergence of net-grammar in communicating agents. Biosystems 38(1), 1–14 (1996)CrossRefGoogle Scholar
  13. 13.
    Hagoort, P.: On Broca, brain and binding: a new framework. Trends in Cognitive Science 9(9), 416–423 (2005)CrossRefGoogle Scholar
  14. 14.
    Jackendoff, R.: Foundations of Language: Brain, Meaning, Grammar, Evolution. Oxford University Press, Oxford (2002)Google Scholar
  15. 15.
    Kay, M.: Functional unification grammar: A formalism for machine translation. In: Proceedings of the International Conference of Computational Linguistics (1984)Google Scholar
  16. 16.
    Kapur, D., Narendran, P.: NP-completeness of the set-unification and matching problems. In: Siekmann, J.H. (ed.) CADE 1986. LNCS, vol. 230, pp. 289–495. Springer, Heidelberg (1986)Google Scholar
  17. 17.
    Langacker, R.W.: Grammar and Conceptualization. Mouton de Gruyter, Den Haag (2000)Google Scholar
  18. 18.
    Minett, J.W., Wang, W.S.-Y.: Language Acquisition, Change and Emergence: Essays in Evolutionary Linguistics. City University of Hong Kong Press, Hong Kong (2005)Google Scholar
  19. 19.
    Pollard, C., Sag, I.: Head-driven phrase structure grammar. University of Chicago Press, Chicago (1994)Google Scholar
  20. 20.
    Russell, S.J., Norvig, P.: Artificial Intelligence: A Modern Approach, 2nd edn. Prentice-Hall, Upper Saddle River, New Jersey 07458 (2003)Google Scholar
  21. 21.
    Sierra-Santibàñez, J.: Prolog Implementation of Fluid Construction Grammar. In: Presented at the First FCG workshop, Paris (2004)Google Scholar
  22. 22.
    Sterling, L., Shapiro, E.: The art of PROLOG. MIT Press, Cambridge (1986)zbMATHGoogle Scholar
  23. 23.
    Steels, L.: Self-organizing vocabularies. In: Langton, C. (ed.) Proceedings of the Conference on Artificial Life V (Alife V) (Nara, Japan) (1996)Google Scholar
  24. 24.
    Steels, L., Loetzsch, M., Bergen, B.: Explaining Language Universals: A Case Study on Perspective Marking (submitted 2005)Google Scholar
  25. 25.
    Smith, K., Kirby, S., Brighton, H.: Iterated Learning: a framework for the emergence of language. Artificial Life 9(4), 371–386 (2003)CrossRefGoogle Scholar
  26. 26.
    Steels, L.: The origins of syntax in visually grounded robotic agents. Artificial Intelligence 103(1-2), 133–156 (1998)zbMATHCrossRefGoogle Scholar
  27. 27.
    Steels, L.: Constructivist Development of Grounded Construction Grammars. In: Scott, D., Daelemans, W., Walker, M. (eds.) Proceedings Annual Meeting Association for Computational Linguistic Conference, Barcelona, pp. 9–19 (2004)Google Scholar
  28. 28.
    Steels, L.: The emergence and evolution of linguistic structure: from lexical to grammatical communication systems. Connection Science 17(3-4), 213–230 (2005)CrossRefGoogle Scholar
  29. 29.
    Steels, L., De Beule, J., Neubauer, N.: Linking in Fluid Construction Grammar. Transactions Royal Flemish Academy for Science and Art. In: Proceedings of BNAIC 2005, pp. 11–18 (2005)Google Scholar
  30. 30.
    Steele Jr., G.L.: Common Lisp, the language, 2nd edn. Digital Press (1990)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • Luc Steels
    • 1
    • 2
  • Joachim De Beule
    • 2
  1. 1.SONY Computer Science Laboratory – Paris 
  2. 2.Artificial Intelligence LaboratoryVrije Universiteit BrusselBrussel

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