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  1. Algebraic Logic, Where Does It Stand Today?Tarek Sayed Ahmed - 2005 - Bulletin of Symbolic Logic 11 (3):465-516.
    This is a survey article on algebraic logic. It gives a historical background leading up to a modern perspective. Central problems in algebraic logic (like the representation problem) are discussed in connection to other branches of logic, like modal logic, proof theory, model-theoretic forcing, finite combinatorics, and Gödel’s incompleteness results. We focus on cylindric algebras. Relation algebras and polyadic algebras are mostly covered only insofar as they relate to cylindric algebras, and even there we have not told the whole story. (...)
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  • Neat Embeddings, Omitting Types, and Interpolation: An Overview.Tarek Sayed Ahmed - 2003 - Notre Dame Journal of Formal Logic 44 (3):157-173.
    We survey various results on the relationship among neat embeddings (a notion special to cylindric algebras), complete representations, omitting types, and amalgamation. A hitherto unpublished application of algebraic logic to omitting types of first-order logic is given.
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  • Some variants of Vaught's conjecture from the perspective of algebraic logic.G. Sagi & D. Sziraki - 2012 - Logic Journal of the IGPL 20 (6):1064-1082.
  • Strongly representable atom structures of cylindric algebras.Robin Hirsch & Ian Hodkinson - 2009 - Journal of Symbolic Logic 74 (3):811-828.
    A cylindric algebra atom structure is said to be strongly representable if all atomic cylindric algebras with that atom structure are representable. This is equivalent to saying that the full complex algebra of the atom structure is a representable cylindric algebra. We show that for any finite n >3, the class of all strongly representable n-dimensional cylindric algebra atom structures is not closed under ultraproducts and is therefore not elementary. Our proof is based on the following construction. From an arbitrary (...)
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  • Omitting types for finite variable fragments and complete representations of algebras.Hajnal Andréka, István Németi & Tarek Sayed Ahmed - 2008 - Journal of Symbolic Logic 73 (1):65-89.
    We give a novel application of algebraic logic to first order logic. A new, flexible construction is presented for representable but not completely representable atomic relation and cylindric algebras of dimension n (for finite n > 2) with the additional property that they are one-generated and the set of all n by n atomic matrices forms a cylindric basis. We use this construction to show that the classical Henkin-Orey omitting types theorem fails for the finite variable fragments of first order (...)
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  • Polyadic and cylindric algebras of sentences.Mohamed Amer & Tarek Sayed Ahmed - 2006 - Mathematical Logic Quarterly 52 (5):444-449.
    In this note we give an interpretation of cylindric algebras as algebras of sentences of first order logic. We show that the isomorphism types of such algebras of sentences coincide with the class of neat reducts of cylindric algebras. Also we show how this interpretation sheds light on some recent results. This is done by likening Henkin's Neat Embedding Theorem to his celebrated completeness proof.
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  • A Note on Neat Reducts.Tarek Sayed Ahmed - 2007 - Studia Logica 85 (2):139-151.
    SC, CA, QA and QEA denote the class of Pinter’s substitution algebras, Tarski’s cylindric algebras, Halmos’ quasi-polyadic and quasi-polyadic equality algebras, respectively. Let . and . We show that the class of n dimensional neat reducts of algebras in K m is not elementary. This solves a problem in [2]. Also our result generalizes results proved in [1] and [2].
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  • Omitting types for finite variable fragments of first order logic.T. Sayed Ahmed - 2003 - Bulletin of the Section of Logic 32 (3):103-107.
  • The class of neat reducts is not Boolean closed.Tarek Sayed Ahmed - 2008 - Bulletin of the Section of Logic 37 (1):51-61.
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  • Neat embedding is not sufficient for complete representability.T. Sayed Ahmed - 2007 - Bulletin of the Section of Logic 36 (1/2):29-35.
  • Vaughts theorem holds for L2 but fails for Ln when n> 2.Mohamed Khaled & T. Sayed Ahmed - 2010 - Bulletin of the Section of Logic 39 (3/4):107-122.
  • Algebras of sentences.Tarek Sayed Ahmed - 2006 - Bulletin of the Section of Logic 35 (1):1-10.
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  • Neat embeddings and amalgamation.Tarek Sayed Ahmed & Basim Samir - 2006 - Bulletin of the Section of Logic 35 (4):163-171.