Pinning countable ordinals
Pinning for pairs of countable ordinals
Planting Kurepa trees and killing Jech-Кunen trees in a model by using one inaccessible cardinal
By an - tree we mean a tree of power and height . Under CH and we call an -tree a Jech-Kunen tree if it has κ-many branches for some κ strictly between and . In this paper we prove that, assuming the existence of one inaccessible cardinal, (1) it is consistent with CH plus that there exist Kurepa trees and there are no Jech-Kunen trees, which answers a question of [Ji2], (2) it is consistent with CH plus that there only exist Kurepa trees with -many branches, which answers another...
P-NDOP and P-decompositions of -saturated models of superstable theories
Given a complete, superstable theory, we distinguish a class P of regular types, typically closed under automorphisms of ℭ and non-orthogonality. We define the notion of P-NDOP, which is a weakening of NDOP. For superstable theories with P-NDOP, we prove the existence of P-decompositions and derive an analog of the first author's result in Israel J. Math. 140 (2004). In this context, we also find a sufficient condition on P-decompositions that implies non-isomorphic models. For this, we investigate...
Počítačová lingvistika ve vztahu k informatice
Poincaré - Verdier duality in o-minimal structures
Here we prove a Poincaré - Verdier duality theorem for the o-minimal sheaf cohomology with definably compact supports of definably normal, definably locally compact spaces in an arbitrary o-minimal structure.
Point-fixe sur un ensemble restreint
Point-reflections in metric plane.
Pointwise convergence and the Wadge hierarchy
We show that if is a separable metrizable space which is not -compact then , the space of bounded real-valued continuous functions on with the topology of pointwise convergence, is Borel--complete. Assuming projective determinacy we show that if is projective not -compact and is least such that is then , the space of real-valued continuous functions on with the topology of pointwise convergence, is Borel--complete. We also prove a simultaneous improvement of theorems of Christensen...
Polarity compatible with a closure system
Polarized category theory, modules, and game semantics.
Polyadic algebras over nonclassical logics
The polyadic algebras that arise from the algebraization of the first-order extensions of a SIC are characterized and a representation theorem is proved. Standard implicational calculi (SIC)'s were considered by H. Rasiowa [19] and include classical and intuitionistic logic and their various weakenings and fragments, the many-valued logics of Post and Łukasiewicz, modal logics that admit the rule of necessitation, BCK logic, etc.
Polyadic spaces of arbitrary compactness numbers
Polynomial time bounded truth-table reducibilities to padded sets
We study bounded truth-table reducibilities to sets of small information content called padded (a set is in the class of all -padded sets, if it is a subset of ). This is a continuation of the research of reducibilities to sparse and tally sets that were studied in many previous papers (for a good survey see [HOW1]). We show necessary and sufficient conditions to collapse and separate classes of bounded truth-table reducibilities to padded sets. We prove that depending on two properties of a...
Polynomially Bounded Sequences and Polynomial Sequences
In this article, we formalize polynomially bounded sequences that plays an important role in computational complexity theory. Class P is a fundamental computational complexity class that contains all polynomial-time decision problems [11], [12]. It takes polynomially bounded amount of computation time to solve polynomial-time decision problems by the deterministic Turing machine. Moreover we formalize polynomial sequences [5].
Poset-valued preference relations
In decision processes some objects may not be comparable with respect to a preference relation, especially if several criteria are considered. To provide a model for such cases a poset valued preference relation is introduced as a fuzzy relation on a set of alternatives with membership values in a partially ordered set. We analyze its properties and prove the representation theorem in terms of particular order reversing involution on the co-domain poset. We prove that for every set of alternatives...
Positive eigenvalues and two-letter generalized words.
Positive functionals and the axiom of choice
Positive Logic with Double Negation
Positive logic with double negation.