Qualified Computations in Functional Logic Programming

  • Rafael Caballero
  • Mario Rodríguez-Artalejo
  • Carlos A. Romero-Díaz
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5649)


Qualification has been recently introduced as a generalization of uncertainty in the field of Logic Programming. In this paper we investigate a more expressive language for First-Order Functional Logic Programming with Constraints and Qualification. We present a Rewriting Logic which characterizes the intended semantics of programs, and a prototype implementation based on a semantically correct program transformation. Potential applications of the resulting language include flexible information retrieval. As a concrete illustration, we show how to write program rules to compute qualified answers for user queries concerning the books available in a given library.


Constraints Functional Logic Programming Program Transformation Qualification Rewriting Logic 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Antoy, S., Echahed, R., Hanus, M.: A needed narrowing strategy. Journal of the ACM 47(4), 776–822 (2000)MathSciNetCrossRefzbMATHGoogle Scholar
  2. 2.
    Arenas, P., Fernández, A.J., Gil, A., López-Fraguas, F.J., Rodríguez-Artalejo, M., Sáenz-Pérez, F.: \(\mathcal{TOY}\), a multiparadigm declarative language. version 2.3.1. Caballero, R., Sánchez, J. (eds.) (2007),
  3. 3.
    Caballero, R., Rodríguez-Artalejo, M., Romero-Díaz, C.A.: Similarity-based reasoning in qualified logic programming. In: PPDP 2008: Proceedings of the 10th international ACM SIGPLAN conference on Principles and Practice of Declarative Programming, pp. 185–194. ACM, New York (2008)Google Scholar
  4. 4.
    Caballero, R., Rodríguez-Artalejo, M., Romero-Díaz, C.A.: A generic scheme for qualified constraint functional logic programming. Technical Report SIC-1-09, Universidad Complutense, Departamento de Sistemas Informáticos y Computación, Madrid, Spain (2009),
  5. 5.
    del Vado Vírseda, R.: Declarative constraint programming with definitional trees. In: Gramlich, B. (ed.) FroCos 2005. LNCS, vol. 3717, pp. 184–199. Springer, Heidelberg (2005)CrossRefGoogle Scholar
  6. 6.
    Guadarrama, S., Muñoz, S., Vaucheret, C.: Fuzzy prolog: A new approach using soft constraint propagation. Fuzzy Sets and Systems 144(1), 127–150 (2004)MathSciNetCrossRefzbMATHGoogle Scholar
  7. 7.
    Hanus, M.: Curry: an integrated functional logic language, version 0.8.2. Hanus, M. (ed.) (2006),
  8. 8.
    López-Fraguas, F.J., Rodríguez-Artalejo, M., del Vado-Virseda, R.: A lazy narrowing calculus for declarative constraint programming. In: Proceedings of the 6th International ACM SIGPLAN Conference on Principles and Practice of Declarative Programming (PPDP 2004), pp. 43–54. ACM Press, New York (2004)Google Scholar
  9. 9.
    López-Fraguas, F.J., Rodríguez-Artalejo, M., del Vado-Vírseda, R.: A new generic scheme for functional logic programming with constraints. Journal of Higher-Order and Symbolic Computation 20(1-2), 73–122 (2007)CrossRefzbMATHGoogle Scholar
  10. 10.
    Moreno, G., Pascual, V.: Formal properties of needed narrowing with similarity relations. Electronic Notes in Theoretical Computer Science 188, 21–35 (2007)CrossRefzbMATHGoogle Scholar
  11. 11.
    Riezler, S.: Quantitative constraint logic programming for weighted grammar applications. In: Retoré, C. (ed.) LACL 1996. LNCS, vol. 1328, pp. 346–365. Springer, Heidelberg (1997)CrossRefGoogle Scholar
  12. 12.
    Riezler, S.: Probabilistic Constraint Logic Programming. PhD thesis, Neuphilologischen Fakultät del Universität Tübingen (1998)Google Scholar
  13. 13.
    Rodríguez-Artalejo, M.: Functional and constraint logic programming. In: Comon, H., Marché, C., Treinen, R. (eds.) CCL 1999. LNCS, vol. 2002, pp. 202–270. Springer, Heidelberg (2001)CrossRefGoogle Scholar
  14. 14.
    Rodríguez-Artalejo, M., Romero-Díaz, C.A.: Quantitative logic programming revisited. In: Garrigue, J., Hermenegildo, M.V. (eds.) FLOPS 2008. LNCS, vol. 4989, pp. 272–288. Springer, Heidelberg (2008)CrossRefGoogle Scholar
  15. 15.
    Sessa, M.I.: Approximate reasoning by similarity-based SLD resolution. Theoretical Computer Science 275(1-2), 389–426 (2002)MathSciNetCrossRefzbMATHGoogle Scholar
  16. 16.
    Subrahmanian, V.S.: Uncertainty in logic programming: Some recollections. Association for Logic Programming Newsletter 20(2) (2007)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  • Rafael Caballero
    • 1
  • Mario Rodríguez-Artalejo
    • 1
  • Carlos A. Romero-Díaz
    • 1
  1. 1.Departamento de Sistemas Informáticos y ComputaciónUniversidad Complutense Facultad de InformáticaMadridSpain

Personalised recommendations