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  1.  28
    Congruence Coherent Symmetric Extended de Morgan Algebras.T. S. Blyth & Jie Fang - 2007 - Studia Logica 87 (1):51-63.
    An algebra A is said to be congruence coherent if every subalgebra of A that contains a class of some congruence on A is a union of -classes. This property has been investigated in several varieties of lattice-based algebras. These include, for example, de Morgan algebras, p-algebras, double p-algebras, and double MS-algebras. Here we determine precisely when the property holds in the class of symmetric extended de Morgan algebras.
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  2.  20
    De Morgan Algebras with a Quasi-Stone Operator.T. S. Blyth, Jie Fang & Lei-bo Wang - 2015 - Studia Logica 103 (1):75-90.
    We investigate the class of those algebras in which is a de Morgan algebra, is a quasi-Stone algebra, and the operations \ and \ are linked by the identity x**º = x*º*. We show that such an algebra is subdirectly irreducible if and only if its congruence lattice is either a 2-element chain or a 3-element chain. In particular, there are precisely eight non-isomorphic subdirectly irreducible Stone de Morgan algebras.
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  3.  11
    On Ideals and Congruences of Distributive Demi-P-Algebras.T. S. Blyth, Jie Fang & Leibo Wang - 2015 - Studia Logica 103 (3):491-506.
    We identify the \-ideals of a distributive demi-pseudocomplemented algebra L as the kernels of the boolean congruences on L, and show that they form a complete Heyting algebra which is isomorphic to the interval \ of the congruence lattice of L where G is the Glivenko congruence. We also show that the notions of maximal \-ideal, prime \-ideal, and falsity ideal coincide.
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  4.  13
    On Endomorphisms of Ockham Algebras with Pseudocomplementation.T. S. Blyth & J. Fang - 2011 - Studia Logica 98 (1-2):237-250.
    A pO -algebra $${(L; f, \, ^{\star})}$$ is an algebra in which ( L ; f ) is an Ockham algebra, $${(L; \, ^{\star})}$$ is a p -algebra, and the unary operations f and $${^{\star}}$$ commute. Here we consider the endomorphism monoid of such an algebra. If $${(L; f, \, ^{\star})}$$ is a subdirectly irreducible pK 1,1 - algebra then every endomorphism $${\vartheta}$$ is a monomorphism or $${\vartheta^3 = \vartheta}$$ . When L is finite the endomorphism monoid of L is (...)
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  5.  10
    The Dual Space of a Finite Simple Ockham Algebra.T. S. Blyth & J. C. Varlet - 1996 - Studia Logica 56 (1-2):3 - 21.
    Let (L; f) be a finite simple Ockham algebra and let (X;g) be its dual space. We first prove that every connected component of X is either a singleton or a generalised crown (i.e. an ordered set that is connected, has length 1, and all vertices of which have the same degree). The representation of a generalised crown by a square (0,1)-matrix in which all line sums are equal is used throughout, and a complete description of X, including the number (...)
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