Abstract
We introduce and study the notions of computable formal context and computable formal concept. We give some examples of computable formal contexts in which the computable formal concepts fail to form a lattice and study the complexity aspects of formal concepts in computable contexts. In particular, we give some sufficient conditions under which the computability or noncomputability of a formal concept could be recognized from its lattice-theoretic properties. We prove the density theorem showing that in a Cantor-like topology every formal concept can be approximated by computable ones. We also show that not all formal concepts have lattice-theoretic approximations as suprema or infima of families of computable formal concepts.
Similar content being viewed by others
References
Ganter B. and Wille R., Formal Concept Analysis: Mathematical Foundations, Springer-Verlag, Berlin; New York (1999).
Rogers H., Theory of Recursive Functions and Effective Computability, McGraw-Hill Book Company, New York; St. Louis; San Francisco; Toronto; London; Sydney (1967).
Barwise J. (ed.), Handbook on Mathematical Logic, North-Holland, Amsterdam; New York; Oxford (1977).
Ershov Yu. L., Decidability Problems and Constructive Models [in Russian], Nauka, Moscow (1980).
Barwise J., Admissible Sets and Structures, Springer-Verlag, Berlin; Gottingen; Heidelberg (1975).
Sacks G. E., Higher Recursion Theory, Springer-Verlag, Heidelberg (1990).
Author information
Authors and Affiliations
Corresponding author
Additional information
__________
Translated from Sibirskiĭ Matematicheskiĭ Zhurnal, Vol. 48, No. 5, pp. 1083–1092, September–October, 2007.
Original Russian Text Copyright © 2007 Morozov A. S. and L’vova M. A.
The first author was supported by the International DFG-RFBR Grant (RFBR 05-01-04003-NNIOa, DFG 436 RUS 113/829/0-1), the Russian Foundation for Basic Research (Grant 05-01-00819-a), and the State Maintenance Program for the Leading Scientific Schools of the Russian Federation (Grant NSh-4413.2006.1).
Rights and permissions
About this article
Cite this article
Morozov, A.S., L’vova, M.A. On computable formal concepts in computable formal contexts. Sib Math J 48, 871–878 (2007). https://doi.org/10.1007/s11202-007-0089-y
Received:
Issue Date:
DOI: https://doi.org/10.1007/s11202-007-0089-y