Geodesic
Strong retracts of unary algebras
Czechoslovak Mathematical Journal, Tome 51 (2001) no. 1, pp. 205-212 Cet article a éte moissonné depuis la source Czech Digital Mathematics Library

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This paper introduces the notion of a strong retract of an algebra and then focuses on strong retracts of unary algebras. We characterize subuniverses of a unary algebra which are carriers of its strong retracts. This characterization enables us to describe the poset of strong retracts of a unary algebra under inclusion. Since this poset is not necessarily a lattice, we give a necessary and sufficient condition for the poset to be a lattice, as well as the full description of the poset.
This paper introduces the notion of a strong retract of an algebra and then focuses on strong retracts of unary algebras. We characterize subuniverses of a unary algebra which are carriers of its strong retracts. This characterization enables us to describe the poset of strong retracts of a unary algebra under inclusion. Since this poset is not necessarily a lattice, we give a necessary and sufficient condition for the poset to be a lattice, as well as the full description of the poset.
Classification : 08A35, 08A60
Keywords: inflations of algebras; retracts of algebras; unary algebras 
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Madarász, Rozália Sz.; Mašulović, Dragan; Tasić, Boža. Strong retracts of unary algebras. Czechoslovak Mathematical Journal, Tome 51 (2001) no. 1, pp. 205-212. http://geodesic.mathdoc.fr/item/CMJ_2001_51_1_a19/

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