This work presents a model-theoretic approach to the study of firstorder theories of classes of BL-chains. Among other facts, we present several classes of BL-algebras, generating the whole variety of BL-algebras, whose firstorder theory has quantifier elimination. Model-completeness and decision problems are also investigated. Then we investigate classes of BL-algebras having (or not having) t...

for x, where A is a given n × n matrix, and b a given n-vector. We have many opportunities to solve linear equations with the same coefficient matrix and different right-hand sides (RHSs). Therefore, block Krylov subspace methods such as the block Bi-CG (Bl-BCG), block Bi-CGSTAB (Bl-BiCGSTAB) [2], block GMRES (Bl-GMRES) and block QMR (Bl-QMR) methods have been developed for solving block linear...

We apply the rough set theory to BL-algebras. As a generalization of filters subalgebras of BL-algebras, we introduce the notion of rough filters subalgebras of BL-algebras and investigate some of their properties.

In this paper we define Baer BL-algebras as BL-algebras with the property that co-annihilator filters are generated by central elements. We use sheaf-theoretic techniques to construct a Baer extension of any BLalgebra, that is to embed any nontrivial BL-algebra A into a Baer BLalgebra A∗. The embedding turns to be an isomorphism if A is itself a Baer BL-algebra. 2000 MSC: 08A72, 03G25, 54B40, 0...

The aim of this paper is to introduce the notion of anti fuzzy (prime) deductive system in BL-algebra and to investigate their properties. It is shown that the set of all deductive systems (with the empty set) of a BL-algebra X is equipotent to a quotient of the set of all anti fuzzy deductive systems of X. The anti fuzzy prime deductive system theorem of BL-algebras is also proved. Anti Fuzzy ...

PURPOSE Burkitt's lymphoma (BL) is a common HIV-associated lymphoma in South Africa. B-cell lymphoma unclassifiable with features intermediate between diffuse large B-cell lymphoma and Burkitt's lymphoma (BL/DLBCL) also occurs in HIV infection. Outcomes of HIV-infected patients with BL or BL/DLBCL in a resource-constrained setting are not defined. METHODS We performed a retrospective study of...