Preserving some properties of large cardinals under mild Cohen extensions
Primariness of some spaces of continuous functions.
Prime and maximal ideals of partially ordered sets
Prime Ideal Theorems and systems of finite character
We study several choice principles for systems of finite character and prove their equivalence to the Prime Ideal Theorem in ZF set theory without Axiom of Choice, among them the Intersection Lemma (stating that if is a system of finite character then so is the system of all collections of finite subsets of meeting a common member of ), the Finite Cutset Lemma (a finitary version of the Teichm“uller-Tukey Lemma), and various compactness theorems. Several implications between these statements...
Prime ideals yield almost maximal ideals
Principal concepts of systems fuzzification. Fuzzification of systems for technical and medical practice. I
Probability in the alternative set theory
Problemas de decisión en ambiente difuso.
Bajo un planteamiento difuso del Problema General de Decisión Unipersonal, se propone un método que permite definir una función de utilidad para este problema. Dicha función se muestra como una familia de funciones de utilidad, la cual se considera como la "utilidad difusa" que sirve para resolver el problema que se plantea en los distintos contextos.
Problems
Procesos de decisión de grupo con preferencias individuales difusas.
Products of ideals of Borel sets
Products of Lindelöf -spaces are Lindelöf – in some models of ZF
The stability of the Lindelöf property under the formation of products and of sums is investigated in ZF (= Zermelo-Fraenkel set theory without AC, the axiom of choice). It is • not surprising that countable summability of the Lindelöf property requires some weak choice principle, • highly surprising, however, that productivity of the Lindelöf property is guaranteed by a drastic failure of AC, • amusing that finite summability of the Lindelöf property takes place if either some weak choice principle...
Products of small modules
Module is said to be small if it is not a union of strictly increasing infinite countable chain of submodules. We show that the class of all small modules over self-injective purely infinite ring is closed under direct products whenever there exists no strongly inaccessible cardinal.
Products, the Baire category theorem, and the axiom of dependent choice
In ZF (i.e., Zermelo-Fraenkel set theory without the Axiom of Choice) the following statements are shown to be equivalent: (i) The axiom of dependent choice. (ii) Products of compact Hausdorff spaces are Baire. (iii) Products of pseudocompact spaces are Baire. (iv) Products of countably compact, regular spaces are Baire. (v) Products of regular-closed spaces are Baire. (vi) Products of Čech-complete spaces are Baire. (vii) Products of pseudo-complete spaces are Baire.
Program for generating fuzzy logical operations and its use in mathematical proofs
Fuzzy logic is one of the tools for management of uncertainty; it works with more than two values, usually with a continuous scale, the real interval . Implementation restrictions in applications force us to use in fact a finite scale (finite chain) of truth degrees. In this paper, we study logical operations on finite chains, in particular conjunctions. We describe a computer program generating all finitely-valued fuzzy conjunctions (-norms). It allows also to select these -norms according to...
Progrès récents sur l’hypothèse du continu
Les travaux récents de Woodin ont considérablement renouvelé la théorie des ensembles en lui apportant une intelligibilité globale et en restaurant son unité. Pour la première fois, ses résultats ouvrent une perspective réaliste de résoudre le problème du continu, et, à tout le moins, ils établissent le caractère irréfutablement signifiant et précis de celui-ci.
Projections of relations
A projection of a relation is defined as a relation of reduced arity. The paper deals with projections of relations in coherence with their reflexivity, symmetry, completeness, regularity, cyclicity and other properties. Relationships between projections of hulls and hulls of projections are also studied.
Projective well-orderings and extensions of Lebesgue measure
Proper forcings and absoluteness in
We show that in the presence of large cardinals proper forcings do not change the theory of with real and ordinal parameters and do not code any set of ordinals into the reals unless that set has already been so coded in the ground model.
Proper translation
We continue our work on weak diamonds [J. Appl. Anal. 15 (1009)]. We show that together with the weak diamond for covering by thin trees, the weak diamond for covering by meagre sets, the weak diamond for covering by null sets, and “all Aronszajn trees are special” is consistent relative to ZFC. We iterate alternately forcings specialising Aronszajn trees without adding reals (the NNR forcing from [“Proper and Improper Forcing”, Ch. V]) and < ω₁-proper -bounding forcings adding reals. We show...