PORTUGALIAE MATHEMATICA Vol. 55, No. 2, pp. 135-166 (1998) |
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Varieties of Distributive Lattices with Unary Operations IIH.A. Priestley and R. SantosMathematical Institute,24/29 St Giles, Oxford OX1 3LB - ENGLAND E-mail: hap@maths.ox.ac.uk Departamento de Matemática, Faculdade de Ciências, Bloco C1, Piso $3^o$, Rua Ernesto Vasconcelos, 1700 Lisboa - PORTUGAL E-mail: rsantos@fc.ul.pt Abstract: This paper extends to the general setting of [11], [25] procedures presented earlier for varieties of Ockham algebras. Given a suitable finitely generated variety $\Cal A$ of distributive-lattice-ordered algebras with unary operations, in which the subdirectly irreducible algebras are assumed to have been pre-determined, a natural duality, free algebras and coproducts can be obtained algorithmically for any prescribed subvariety of $\Cal A$. Further, the meet-irreducible members of the lattice of equational theories of $\Cal A$ can be written down. The theory is illustrated by carrying this programme through for varieties of double $\scat{MS}$-algebras. Keywords: Natural duality; Priestley duality; free algebra; double MS-algebra. Classification (MSC2000): 06D05, 06D25, 03G20, 08B99 Full text of the article:
Electronic version published on: 29 Mar 2001. This page was last modified: 27 Nov 2007.
© 1998 Sociedade Portuguesa de Matemática
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