-completeness and fixpoint properties
It is known that for a nonempty topological space and a nonsingleton complete lattice endowed with the Scott topology, the partially ordered set of all continuous functions from into is a continuous lattice if and only if both and the open set lattice are continuous lattices. This result extends to certain classes of -distributive lattices, where is a subset system replacing the system of all directed subsets (for which the -distributive complete lattices are just the continuous...
The concept of a -ideal in -distributive posets is introduced. Several properties of -ideals in -distributive posets are established. Further, the interrelationships between -ideals and -ideals in -distributive posets are investigated. Moreover, a characterization of prime ideals to be -ideals in -distributive posets is obtained in terms of non-dense ideals. It is shown that every -ideal of a -distributive meet semilattice is semiprime. Several counterexamples are discussed.
Several characterizations of 0-distributive posets are obtained by using the prime ideals as well as the semiprime ideals. It is also proved that if every proper -filter of a poset is contained in a proper semiprime filter, then it is -distributive. Further, the concept of a semiatom in 0-distributive posets is introduced and characterized in terms of dual atoms and also in terms of maximal annihilator. Moreover, semiatomic 0-distributive posets are defined and characterized. It is shown that...
Let be a type of algebras. A valuation of terms of type is a function assigning to each term of type a value . For , an identity of type is said to be -normal (with respect to valuation ) if either or both and have value . Taking with respect to the usual depth valuation of terms gives the well-known property of normality of identities. A variety is called -normal (with respect to the valuation ) if all its identities are -normal. For any variety , there is a least...
We show that each sequentially continuous (with respect to the pointwise convergence) normed measure on a bold algebra of fuzzy sets (Archimedean -algebra) can be uniquely extended to a sequentially continuous measure on the generated Łukasiewicz tribe and, in a natural way, the extension is maximal. We prove that for normed measures on Łukasiewicz tribes monotone (sequential) continuity implies sequential continuity, hence the assumption of sequential continuity is not restrictive. This yields...
We introduce some particular classes of filters and order-ideals in distributive semilattices, called -filters and -order-ideals, respectively. In particular, we study -filters and -order-ideals in distributive quasicomplemented semilattices. We also characterize the filters-congruence-cokernels in distributive quasicomplemented semilattices through -order-ideals.
In a 0-distributive lattice sufficient conditions for an -ideal to be an annihilator ideal and prime ideal to be an -ideal are given. Also it is proved that the images and the inverse images of -ideals are -ideals under annihilator preserving homomorphisms.