Hájek Petr, prof., RNDr., DrSc.


Born February 6, 1940 in Prague

Study and professional preparation

Graduated from Faculty of Mathematics and Physics of Charles University (CU) in 1962, thesis on algebra, post-graduate student at the Institute of Mathematics of the Czechoslovak Academy of Sciences (CSAS), later Academy of sciences of the Czech Republic (AS CR; (mathematical logic, PhD. thesis on set theory); CSc. in 1965; DrSc. 1990; Assist. prof. (CU) 1993; Honorarprofessor of the Technical University in Vienna from 1994. Professor (CU) 1997.


Institute of Mathematics CSAS/AS CR to 1992 (last as head scientific worker), from March 1992 to the end of February 2000, Director of the Institute of Computer Science AS CR; now senior scientific worker there.

Domain of expertise

Mathematical logic and logical foundations of computer science. Present topic of main activity; mathematical (deductive) fuzzy logic as a many-valued logic with a comparative notion of truth. Over 200 scientific papers (see selection below).

Membership and positions in international organizations and societies


Selection of publications

A. Books

B.Some selected papers

  1. What is Mathematical Fuzzy Logic.Fuzzy Sets and Systems, Vol. 157, 2006, pp. 597-603
  2. On Arithmetic in the Cantor-Lukasiewicz Fuzzy Set Theory. Archive for Mathematical Logic, Vol. 44, 2005, pp. 763-782
  3. Arithmetical Complexity of Fuzzy Predicate Logics - A Survey. Soft Computing, Vol. 9, 2005, pp. 935-941
  4. (with Holeňa M.)Formal Logics of Discovery and Hypothesis Formation by Machine. Theoretical Computer Science, Vol. 292, 2003, pp. 345-357
  5. A New Small Emendation of Gödels Ontological Proof. - Studia Logica, Vol. 71, 2002, pp. 149-164
  6. (with Shepherdson J.) A Note on the Notion of Truth in Fuzzy Logic. Annals of Pure and Applied Logic, Vol. 109, 2001, pp. 65-69
  7. (with Paris J., Shepherdson J.) The Liar Paradox and Fuzzy Logics. Journal of Symbolic Logic, Vol. 65, 2000, No. 1, pp. 339-346
  8. Interpretability and Fragments of Arithmetic.In: Arithmetic, Proof Theory and Computational Complexity. (Ed.: Clote P., Krajíček J.) - Oxford, Clarendon Press 1993, pp. 185-196
  9. (with Clote P.,Paris J.)On Some Formalized Conservation Results in Arithmetic. Archive for Mathematical Logic, Vol. 31, 1991, pp. 201-218
  10. (with Montagna F.) The Logic of Pi-1 Conservativity. Archive for Mathematical Logic, Vol. 30, 1990, pp. 113-123
  11. (with Kučera A.) On Recursion Theory in IE1. The Journal Symbolic of Logic, Vol. 54, 1989, pp. 576-589
  12. Arithmetical Interpretations of Dynamic Logic. Journal of Symbolic Logic, Vol. 48, 1983, pp. 704-71
  13. (with Hájková M.) On Interpretability in Theories Containing Arithmetic. Fundamenta Mathematicae, Vol. 76, 1972, pp. 131-137
  14. (with Havel I., Chytil M.) The GUHA-Method of Automatic Hypotheses Determination. Computing, Vol. 1, 1966, pp. 293-308
  15. The Consistency of Church's Alternatives. Bull. Acad. Polon. Sci., Vol. 14, 1966, pp. 31-47
Full list of publications

Freely available on internet

Učební texty


    Institute of computer science
    Academy of sciences of the Czech Republic
    Pod vodárenskou věží 2
    182 07 Prague
    Czech Republic
    e-mail: hajek[-at-]cs.cas.cz
    phone:  (+420) 266053760