Angel Vasilev Ditchev

Angel Vasilev Ditchev

Associate professor
PhD
Email: 
ditchev@fmi.uni-sofia.bg
Phone: 
+359 2 8161-505
Room: 
Faculty of Physics, room 242
Office hours: 

Monday 14:30-15:30

Publications

  1. Connection between computability in the Moschovakis' sense and partial recursiveness by enumerations (in Bulgarian), M.Sc. Thesis, Sofia University
  2. Connection between computability in the Moschovakis' sense and partial recursiveness by enumerations (in Russian), Serdica 7, 1981, pp. 117 - 130
  3. An example of a set of natural numbers M not equivalent to the set M2 (in Bulgarian), In: Mathematics and Mathematical Education, Sofia, 1981, pp. 137 - 140
  4. On the m-equivalence of Cartesian degrees of sets of natural numbers, Serdica, 9, 1983, pp. 43 - 48
  5. Existence of sets of natural numbers M for which Mk+1 is not m-equivalent to Mk, In the Proceedings of the conference dedicated to 1300 years of foundation of Bulgaria, October 20 - 22 1981, Physics & Mathematics, Shumen, 1982, pp. 205 - 221
  6. Computability in Moschovakis' sense and its relations with partial recursiveness by enumerations In: Mathematical Logic, Ed. D. Skordev, Sofia, BAS, 1984, pp. 233-251.
  7. Unreducability of some Cartesian degrees to the others and a relationship between two kinds of computability (in Bulgarian), Ph.D. Thesis, Sofia University, Faculty of Mathematics and Informatics, 1983.
  8. On Skordev's Conjecture (in Russian), Algebra & Logic 24, No 4 (1985), pp. 379 - 391.
  9. Search computability and computability with numberings are equivalent in the case of finite sets of objects, In: Mathematical Logic and Its Applications, Ed. D. Skordev, Plenum Press, New York and London, 1987, pp. 233 - 242
  10. Some results on bounded truth-table degrees, Zeit. fur Math. Log. und Grundl. der Math., 36, No 3 (1990) pp. 263 - 271.
  11. Effective enumerations of families of finite sets of natural numbers, Zeit. fur Math. Log. und Grundl. der Math., 37(1991), pp. 301 - 306
  12. On the effective enumerations of partial structures, Annuaire de l' Universite de Sofia, Faculte de Mathematiques et Informatique, livre 1, 83 (1989), 29 - 37
  13. Examples of structures which do not admit recursive presentations, Annuaire de l' Universite de Sofia, Faculte de Mathematiques et Informatique, livre 1, 85 (1991), 3 - 11
  14. On bounded truth-table degrees and positive degrees, Annuaire de l' Universite de Sofia, Faculte de Mathematiques et Informatique, livre 1, 86 (1992), 61 - 71
  15. On the effective enumerations of structures with unary functions and predicates, Annuaire de l' Universite de Sofia, Faculte de Mathematiques et Informatique, livre 1, 91 (1997), 7 - 12
  16. Characterization of the structures which admit effective enumerations, Annuaire de l' Universite de Sofia, Faculte de Mathematiques et Informatique, livre 1, 92 (1998), 7 - 16
  17. Еffective enumeration of families of recursive functions, Annuaire de l' Universite de Sofia, Faculte de Mathematiques et Informatique, livre 1, 93 (1999), 31 - 37
  18. Some results on the upper-semilattice of r.e. m-degrees inside a single r.e. tt-degree, Annuaire de l' Universite de Sofia, Faculte de Mathematiques et Informatique, livre 1, 96 (2004), 23 - 34
Books
  • Theory of programs (Co-author with Ivan Soskov). Sofia, Sofia University Publisher, 1996 (in Bulgarian)