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Coproducts of De Morgan algebras

Published online by Cambridge University Press:  17 April 2009

William H. Cornish
Affiliation:
School of Mathematical Sciences, Flinders University of South Australia, Bedford Park, South Australia.
Peter R. Fowler
Affiliation:
School of Mathematical Sciences, Flinders University of South Australia, Bedford Park, South Australia.
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Abstract

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The dual of the category of De Morgan algebras is described in terms of compact totally ordered-disconnected ordered topological spaces which possess an involutorial homeomorphism that is also a dual order-isomorphism. This description is used to study the coproduct of an arbitrary collection of De Morgan algebras and also to represent the coproduct of two De Morgan algebras in terms of the continuous order-preserving functions from the Priestley space of one algebra to the other algebra, endowed with the discrete topology. In addition, it is proved that the coproduct of a family of Kleene algebras in the category of De Morgan algebras is the same as the coproduct in the subcategory of Kleene algebras if and only if at most one of the algebras is not boolean.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1977

References

[1]Balbes, Raymond and Dwinger, Philip, Distributive lattices (University of Missouri Press, Columbia, Missouri, 1974).Google Scholar
[2]Białynicki-Birula, A., “Remarks on quasi-boolean algebras”, Bull. Acad. Polon. Sci. Cl. III 5 (1957), 615619.Google Scholar
[3]Białynicki-Birula, A. and Rasiowa, H., “On the representation of quasi-boolean algebras”, Bull. Acad. Polon. Soi. Cl. III 5 (1957), 259261.Google Scholar
[4]Cignoli, Roberto, “Injective De Morgan and Kleene algebras”, Proc. Amer. Math. Soc. 47 (1975), 269278.Google Scholar
[5]Cornish, William H., “Compactness of the clopen topology and applications to ideal theory”, General Topology and Appl. 5 (1975), 347359.CrossRefGoogle Scholar
[6]Cornish, William H., “On H. Priestley's dual of the category of bounded distributive lattices”, Mat. Vesnik 12 (27) (1975), 329332.Google Scholar
[7]Cornish, William H., “Ordered topological spaces and the coproduct of bounded distributive lattices”, Colloq. Math. (to appear).Google Scholar
[8]Davey, Brian A., “Free products of bounded distributive lattices”, Algebra Universalis 4 (1974), 106107.CrossRefGoogle Scholar
[9]Grätzer, George, Lattice theory. First concepts and distributive lattices (Freeman, San Francisco, 1971).Google Scholar
[10]Grätzer, G. and Lakser, H., “The structure of pseudocomplemented distributive lattices. II: Congruence extension and amalgamation”, Trans. Amer. Math. Soc. 156 (1971), 343358.Google Scholar
[11]Kalman, J.A., “Lattices with involution”, Trans. Amer. Math. Soc. 87 (1958), 485491.CrossRefGoogle Scholar
[12]Petrescu, Iona, “Injective objects in the category of Morgan algebras”, Rev. Roumanie Math. Pures. Appl. 16 (1971), 921926.Google Scholar
[13]Taylor, Walter, “Residually small varieties”, Algebra Universalis 2 (1972), 3353.Google Scholar