On hereditarily separable Hausdorff spaces in the constructible universe
On hidden variables
On homogeneous coverings of Euclidean spaces.
On homomorphisms of fuzzy groups.
On homotopical equivalence of tolerance spaces
On Horn Theories.
On ideal theory of hoops
In this paper, we define and characterize the notions of (implicative, maximal, prime) ideals in hoops. Then we investigate the relation between them and prove that every maximal implicative ideal of a -hoop with double negation property is a prime one. Also, we define a congruence relation on hoops by ideals and study the quotient that is made by it. This notion helps us to show that an ideal is maximal if and only if the quotient hoop is a simple MV-algebra. Also, we investigate the relationship...
On ideals and congruences in BCC-algebras
We introduce a new concept of ideals in BCC-algebras and describe connections between such ideals and congruences.
On ideals in De Morgan residuated lattices
In this paper, we introduce a new class of residuated lattices called De Morgan residuated lattices, we show that the variety of De Morgan residuated lattices includes important subvarieties of residuated lattices such as Boolean algebras, MV-algebras, BL-algebras, Stonean residuated lattices, MTL-algebras and involution residuated lattices. We investigate specific properties of ideals in De Morgan residuated lattices, we state the prime ideal theorem and the pseudo-complementedness of the ideal...
On ideals in Hilbert algebras
On ideals with projective bases.
On idempotent binary relations on a finite set
On idempotent filters
On idempotent modifications of -algebras
The notion of idempotent modification of an algebra was introduced by Ježek. He proved that the idempotent modification of a group is subdirectly irreducible. For an -algebra we denote by and the idempotent modification, the underlying set or the underlying lattice of , respectively. In the present paper we prove that if is semisimple and is a chain, then is subdirectly irreducible. We deal also with a question of Ježek concerning varieties of algebras.
On inaccessible cardinal numbers.
On independence of the relations of epimorphy and embeddability on the variety of all lattices.
On independent recursive axiomatisation in intuitionistic logic
On infinite partitions of lines and space
Given a partition P:L → ω of the lines in , n ≥ 2, into countably many pieces, we ask if it is possible to find a partition of the points, , so that each line meets at most m points of its color. Assuming Martin’s Axiom, we show this is the case for m ≥ 3. We reduce the problem for m = 2 to a purely finitary geometry problem. Although we have established a very similar, but somewhat simpler, version of the geometry conjecture, we leave the general problem open. We consider also various generalizations...
On information storage and retrieval systems
On injective -modules.