Abstract
A quasi-decomposition of a Hilbert algebra A is a pair (C, D) of its subalgebras such that (i) every element a ∈ A is a meet c ∧ d with c ∈ C, d ∈ D, where c and d are compatible (i.e., c → d = c → (c ∧ d)), and (ii) d → c = c (then c is uniquely defined). Quasi-decompositions are intimately related to the so-called triple construction of Hilbert algebras, which we reinterpret as a construction of quasidirect products. We show that it can be viewed as a generalization of the semidirect product construction, that quasidirect products has a certain universal property and that they can be characterised in terms of short exact sequences. We also discuss four classes of Hilbert algebras and give for each of them conditions on a quasi-decomposition of an arbitrary Hilbert algebra A under which A belongs to this class.
(Communicated by Anatolij Dvurečenskij)
References
[1] Chajda, I.—Länger, H.—Paseka, J.: Algebraic aspects of relatively pseudocomplemented posets, Order 37 (2020), 1–29.10.1007/s11083-019-09488-1Search in Google Scholar
[2] Cīrulis, J.: Multipliers, closure endomorphisms and quasi-decompositions of a Hilbert algebra. In: Contributions to General Algebra, Vol. 16. Verl. Johannes Heyn, Klagenfurt, 2005, pp. 25–34.Search in Google Scholar
[3] Cīrulis, J.: Hilbert algebras as implicative partial semilattices, CentrL Eur. J. Math. 5 (2007), 264–279.10.2478/s11533-007-0008-2Search in Google Scholar
[4] Cīrulis, J.: Relatively pseudocomplemented Hilbert algebras, Cent. Eur. J. Math. 6 (2008), 189–190.10.2478/s11533-008-0014-zSearch in Google Scholar
[5] Cīrulis, J.: Implication in sectionally pseudocomplemented posets, Acta Sci. Math. (Szeged) 74 (2008), 477–491.Search in Google Scholar
[6] Cīrulis, J.: Lattice of closure endomorphisms of a Hilbert algebra, Asian-European J. Math. 12 (2019), Art. ID 19500082.10.1142/S1793557119500827Search in Google Scholar
[7] Cīrulis, J.: Modal Hilbert algebras and their triple representation, J. Mult.-Val. Log. Soft Comput., to appear, available at https://www.researchgate.net/publication/341600258.Search in Google Scholar
[8] Diego, A.: Sobre Algebras de Hilbert. Notas de Logica Mat. 12, Inst. Mat. Univ. Nac. del Sur, Bahia Blanca, 1965.Search in Google Scholar
[9] Katriňák, T.: Bemerkung über pseudokomplementären halbgeordneten Mengen, Acta Fac. Rerum Nat. Univ. Comenian., Math. 19 (1968), 181–185.Search in Google Scholar
[10] Katriňák, T.: Pseudokomlementäre Halbverbande, Mat. Časopis 18 (1968), 121–143.Search in Google Scholar
[11] Katriňák, T.: Die Kennzeichnung der distributiven pseudo-komplementären Halbverbände, J. Reine Angew. Math. 241 (1970), 160–179.10.1515/crll.1970.241.160Search in Google Scholar
[12] Köhler, P.: The semigroup of varieties of Brouwerian semilattices, Trans. Amer. Math. Soc. 241 (1978), 331–342.10.1090/S0002-9947-1978-0480230-6Search in Google Scholar
[13] Marsden, E. L.: Compatible elements in implicative models, J. Philos. Logic 1 (1972), 156–161.10.1007/BF00650494Search in Google Scholar
[14] Marsden, E. L.: A note on implicative models, Notre Dame J. Formal Logic 14 (1973), 139–144.10.1305/ndjfl/1093890823Search in Google Scholar
[15] Marsden, E. L.: Reducible implicative models, J. Natur. Sci. Math. 14 (1974), 23–34.10.1305/ndjfl/1093890823Search in Google Scholar
[16] Nemitz, W. C.: Implicative semilattices, Trans. Amer. Math. Soc. 117 (1965), 128–142.10.1090/S0002-9947-1965-0176944-9Search in Google Scholar
[17] Nemitz, W. C.: Extensions of Brouwerian semilattices, Houston J. Math. 10 (1984), 545–558.Search in Google Scholar
[18] Rasiowa, H.: An Algebraic Approach to Non-classical Logics, PWN, North-Holland, Warszawa e.a., 1974.Search in Google Scholar
[19] Rhodes, J. B.: Modular and distributive semilattices, Trans. Amer. Math. Soc. 201 (1975), 31–41.10.1090/S0002-9947-1975-0351935-XSearch in Google Scholar
[20] Rose, H. E.: A Course on Finite Groups, Springer, Berlin, 2009.10.1007/978-1-84882-889-6Search in Google Scholar
[21] Rudeanu, S.: On relatively pseudocomplemented posets and Hilbert algebras, An. Ṣtiinṭ. Univ. Al. I. Cuza Iaṣi, N. Ser., Secṭ. Ia 31 (1985), Suppl., 74–77.Search in Google Scholar
[22] Schmidt, J.: Quasi-decompositions, exact sequences, and triple sums of semigroups I, Colloq. Math. Soc. J. Bolyai 17 (1975), 365–397.Search in Google Scholar
[23] Schmidt, J.: Quasi-decompositions, exact sequences, and triple sums of semigroups II, Colloq. Math. Soc. J. Bolyai 17 (1975), 399–428.10.1016/B978-0-7204-0725-9.50035-6Search in Google Scholar
[24] Venkatanarasimhan, P. V.: Pseudo-complements in posets, Proc. Amer. Math. Soc. 28 (1971), 9–17.10.1090/S0002-9939-1971-0272687-XSearch in Google Scholar
[25] Wickless, W. J.: A First Graduate Course in Abstract Algebra, New York, NY, Marcel Dekker, 2004.Search in Google Scholar
© 2021 Mathematical Institute Slovak Academy of Sciences
Articles in the same Issue
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Articles in the same Issue
- Regular Papers
- Quasi-decompositions and quasidirect products of Hilbert algebras
- Residuation in finite posets
- On a problem in the theory of polynomials
- Fekete-Szegö problem for starlike functions connected with k-Fibonacci numbers
- Mapping properties of the Bergman projections on elementary Reinhardt domains
- Lemniscate-like constants and infinite series
- On the Oscillation of second order nonlinear neutral delay differential equations
- Oscillation theorems for certain second-order nonlinear retarded difference equations
- De la Vallée Poussin inequality for impulsive differential equations
- Hs-Boundedness of a class of Fourier Integral Operators
- Dynamical behavior of a P-dimensional system of nonlinear difference equations
- Some inequalities for exponentially convex functions on time scales
- Impact of different types of non linearity on the oscillatory behavior of higher order neutral difference equations
- The sine extended odd Fréchet-G family of distribution with applications to complete and censored data
- A new two-parameter lifetime distribution with flexible hazard rate function: Properties, applications and different method of estimations
- Simulations of nonlinear parabolic PDEs with forcing function without linearization
- An existence level for the residual sum of squares of the power-law regression with an unknown location parameter
- A relationship between the category of chain MV-algebras and a subcategory of abelian groups