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Bing, Kurt 1955. On arithmetical classes not closed under direct union. Proceedings of the American Mathematical Society, Vol. 6, Issue. 5, p. 836.
  • CrossRef
  • Google Scholar
Tarski, Alfred 1955. Contributions to the theory of models. III. Indagationes Mathematicae (Proceedings), Vol. 58, Issue. , p. 56.
  • CrossRef
  • Google Scholar
Oberschelp, Arnold 1958. Über die Axiome Produkt-Abgeschlossener Arithmetischer Klassen. Archiv für Mathematische Logik und Grundlagenforschung, Vol. 4, Issue. 3-4, p. 95.
  • CrossRef
  • Google Scholar
Lyndon, R. C. 1959. Properties preserved under algebraic constructions. Bulletin of the American Mathematical Society, Vol. 65, Issue. 5, p. 287.
  • CrossRef
  • Google Scholar
Lyndon, R. C. 1959. Existential Horn sentences. Proceedings of the American Mathematical Society, Vol. 10, Issue. 6, p. 994.
  • CrossRef
  • Google Scholar
1963. Introduction to Model Theory and to the Metamathematics of Algebra. Vol. 32, Issue. , p. 272.
  • CrossRef
  • Google Scholar
Keisler, H. Jerome 1965. Reduced products and Horn classes. Transactions of the American Mathematical Society, Vol. 117, Issue. 0, p. 307.
  • CrossRef
  • Google Scholar
Galvin, Fred 1970. Horn sentences. Annals of Mathematical Logic, Vol. 1, Issue. 4, p. 389.
  • CrossRef
  • Google Scholar
1971. The Metamathematics of Algebraic Systems - Collected Papers: 1936–1967. Vol. 66, Issue. , p. 474.
  • CrossRef
  • Google Scholar
Schwartz, Dietrich 1972. Mengenlehre über vorgegebenen algebraischen Systemen. Mathematische Nachrichten, Vol. 53, Issue. 1-6, p. 365.
  • CrossRef
  • Google Scholar
Henschen, L. and Wos, L. 1974. Unit Refutations and Horn Sets. Journal of the ACM, Vol. 21, Issue. 4, p. 590.
  • CrossRef
  • Google Scholar
Henschen 1976. Semantic Resolution for Horn Sets. IEEE Transactions on Computers, Vol. C-25, Issue. 8, p. 816.
  • CrossRef
  • Google Scholar
Matrosov, V. M. Vasil'ev, S. N. Karatuev, V. G. Novikov, M. A. Sumenkov, E. A. and Yadykin, S. A. 1979. Machine deduction of theorems on dynamic properties with vector functions of Lyapunov. Cybernetics, Vol. 15, Issue. 2, p. 184.
  • CrossRef
  • Google Scholar
BONCZEK, ROBERT H. HOLSAPPLE, CLYDE W. and WHINSTON, ANDREW B. 1981. Foundations of Decision Support Systems. p. 358.
  • CrossRef
  • Google Scholar
Fagin, Ronald 1982. Horn clauses and database dependencies. Journal of the ACM, Vol. 29, Issue. 4, p. 952.
  • CrossRef
  • Google Scholar
Sidhu, Deepinder P. 1984. Logic programming applied to hardware design specification and verification. ACM SIGMICRO Newsletter, Vol. 15, Issue. 4, p. 309.
  • CrossRef
  • Google Scholar
Broy, M. Wirsing, M. and Pair, C. 1984. A systematic study of models of abstract data types. Theoretical Computer Science, Vol. 33, Issue. 2-3, p. 139.
  • CrossRef
  • Google Scholar
Bonczek, Robert H. Holsapple, Clyde W. and Whinston, Andrew B. 1984. Advances in Computers Volume 23. Vol. 23, Issue. , p. 141.
  • CrossRef
  • Google Scholar
Balbin, Isaac and Lecot, Koenraad 1985. Logic Programming. p. 10.
  • CrossRef
  • Google Scholar
Haiman, Mark 1985. Proof theory for linear lattices. Advances in Mathematics, Vol. 58, Issue. 3, p. 209.
  • CrossRef
  • Google Scholar
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On sentences which are true of direct unions of algebras1
  • Volume 16, Issue 1
  • Alfred Horn (a1)
  • DOI: https://doi.org/10.2307/2268661
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On sentences which are true of direct unions of algebras1
  • Volume 16, Issue 1
  • Alfred Horn (a1)
  • DOI: https://doi.org/10.2307/2268661
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On sentences which are true of direct unions of algebras1
  • Volume 16, Issue 1
  • Alfred Horn (a1)
  • DOI: https://doi.org/10.2307/2268661
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