Program for generating fuzzy logical operations and its use in mathematical proofs

Tomáš Bartušek; Mirko Navara

Kybernetika (2002)

  • Volume: 38, Issue: 3, page [235]-244
  • ISSN: 0023-5954

Abstract

top
Fuzzy logic is one of the tools for management of uncertainty; it works with more than two values, usually with a continuous scale, the real interval [ 0 , 1 ] . Implementation restrictions in applications force us to use in fact a finite scale (finite chain) of truth degrees. In this paper, we study logical operations on finite chains, in particular conjunctions. We describe a computer program generating all finitely-valued fuzzy conjunctions ( t -norms). It allows also to select these t -norms according to various criteria. Using this program, we formulated several conjectures which we verified by theoretical proofs, thus obtaining new mathematical theorems. We found out several properties of t -norms that are quite surprising. As a consequence, we give arguments why there is no “satisfactory" finitely-valued conjunction. Such an operation is desirable, e. g., for search in large databases. We present an example demonstrating both the motivation and the difficulties encountered in using many-valued conjunctions. As a by-product, we found some consequences showing that the characterization of diagonals of finitely-valued conjunctions differs substantially from that obtained for t -norms on [ 0 , 1 ] .

How to cite

top

Bartušek, Tomáš, and Navara, Mirko. "Program for generating fuzzy logical operations and its use in mathematical proofs." Kybernetika 38.3 (2002): [235]-244. <http://eudml.org/doc/33579>.

@article{Bartušek2002,
abstract = {Fuzzy logic is one of the tools for management of uncertainty; it works with more than two values, usually with a continuous scale, the real interval $[0,1]$. Implementation restrictions in applications force us to use in fact a finite scale (finite chain) of truth degrees. In this paper, we study logical operations on finite chains, in particular conjunctions. We describe a computer program generating all finitely-valued fuzzy conjunctions ($t$-norms). It allows also to select these $t$-norms according to various criteria. Using this program, we formulated several conjectures which we verified by theoretical proofs, thus obtaining new mathematical theorems. We found out several properties of $t$-norms that are quite surprising. As a consequence, we give arguments why there is no “satisfactory" finitely-valued conjunction. Such an operation is desirable, e. g., for search in large databases. We present an example demonstrating both the motivation and the difficulties encountered in using many-valued conjunctions. As a by-product, we found some consequences showing that the characterization of diagonals of finitely-valued conjunctions differs substantially from that obtained for $t$-norms on $[0,1]$.},
author = {Bartušek, Tomáš, Navara, Mirko},
journal = {Kybernetika},
keywords = {$t$-norm; finitely valued conjunction; -norm; finitely-valued conjunction},
language = {eng},
number = {3},
pages = {[235]-244},
publisher = {Institute of Information Theory and Automation AS CR},
title = {Program for generating fuzzy logical operations and its use in mathematical proofs},
url = {http://eudml.org/doc/33579},
volume = {38},
year = {2002},
}

TY - JOUR
AU - Bartušek, Tomáš
AU - Navara, Mirko
TI - Program for generating fuzzy logical operations and its use in mathematical proofs
JO - Kybernetika
PY - 2002
PB - Institute of Information Theory and Automation AS CR
VL - 38
IS - 3
SP - [235]
EP - 244
AB - Fuzzy logic is one of the tools for management of uncertainty; it works with more than two values, usually with a continuous scale, the real interval $[0,1]$. Implementation restrictions in applications force us to use in fact a finite scale (finite chain) of truth degrees. In this paper, we study logical operations on finite chains, in particular conjunctions. We describe a computer program generating all finitely-valued fuzzy conjunctions ($t$-norms). It allows also to select these $t$-norms according to various criteria. Using this program, we formulated several conjectures which we verified by theoretical proofs, thus obtaining new mathematical theorems. We found out several properties of $t$-norms that are quite surprising. As a consequence, we give arguments why there is no “satisfactory" finitely-valued conjunction. Such an operation is desirable, e. g., for search in large databases. We present an example demonstrating both the motivation and the difficulties encountered in using many-valued conjunctions. As a by-product, we found some consequences showing that the characterization of diagonals of finitely-valued conjunctions differs substantially from that obtained for $t$-norms on $[0,1]$.
LA - eng
KW - $t$-norm; finitely valued conjunction; -norm; finitely-valued conjunction
UR - http://eudml.org/doc/33579
ER -

References

top
  1. Bartušek T., Fuzzy Operations on Finite Sets of Truth Values (in Czech), Diploma Thesis, Czech Technical University, Praha 2001 
  2. Baets B. De, Mesiar R., 10.1016/S0165-0114(98)00259-0, Fuzzy Sets and Systems 104 (1999), 61–75 (1999) Zbl0935.03060MR1685810DOI10.1016/S0165-0114(98)00259-0
  3. Baets B. De, Mesiar R., Discrete triangular norms, In: Topological and Algebraic Structures (E. P. Klement and S. Rodabaugh, eds.), Universität Linz 1999, pp. 6–10 (1999) 
  4. Baets B. De, Mesiar R., Discrete triangular norms, In: Topological and Algebraic Structures in Fuzzy Sets: Recent Developments in the Mathematics of Fuzzy Sets (S. Rodabaugh and E. P. Klement, eds.). Kluwer Academic Publishers, 2002, to appear Zbl1037.03046MR2046749
  5. Drossos C., Navara M., Matrix composition of t-norms, In: Enriched Lattice Structures for Many-Valued and Fuzzy Logics (S. Gottwald and E. P. Klement, eds.), Univ. Linz 1997, pp. 95–100 (1997) 
  6. Godo L., Sierra C., A new approach to connective generation in the framework of expert systems using fuzzy logic, In: Proc. 11th Internat. Symposium on Multiple–Valued Logic, IEEE Computer Society Press, Palma de Mallorca 1988, pp. 157–162 (1988) 
  7. Klement E. P., Mesiar, R., Pap E., Triangular Norms, Kluwer, Dordrecht – Boston – London 2000 Zbl1087.20041MR1790096
  8. Mayor G., Torrens J., 10.1002/int.4550080703, Internat. J. Intell. Syst. 8 (1993), 771–778 (1993) Zbl0785.68087DOI10.1002/int.4550080703
  9. Mamdani E. H., Assilian S., 10.1016/S0020-7373(75)80002-2, J. Man-Machine Stud. 7 (1975), 1–13 (1975) Zbl0301.68076DOI10.1016/S0020-7373(75)80002-2
  10. Mesiar R., Navara M., 10.1016/S0165-0114(98)00256-5, Fuzzy Sets and Systems 104 (1999), 34–41 (1999) Zbl0972.03052MR1685807DOI10.1016/S0165-0114(98)00256-5
  11. Moser B., Navara M., Conditionally firing rules extend the possibilities of fuzzy controllers, In: Proc. Internat. Conf. Computational Intelligence for Modelling, Control and Automation (M. Mohammadian, ed.), IOS Press, Amsterdam 1999, pp. 242–245 (1999) Zbl0988.93050
  12. Viceník P., 10.1016/S0165-0114(98)00253-X, Fuzzy Sets and Systems 104 (1999), 15–18 (1999) Zbl0953.26009MR1685804DOI10.1016/S0165-0114(98)00253-X

NotesEmbed ?

top

You must be logged in to post comments.

To embed these notes on your page include the following JavaScript code on your page where you want the notes to appear.

Only the controls for the widget will be shown in your chosen language. Notes will be shown in their authored language.

Tells the widget how many notes to show per page. You can cycle through additional notes using the next and previous controls.

    
                

Note: Best practice suggests putting the JavaScript code just before the closing </body> tag.