Some remarks on a Telgarsky's conjecture concerning products of paracompact spaces

R. Telgarsky conjectured that if X is a paracompact space then the product X×Y is paracompact for every paracompact space Y if and only if the first player of the G(DC,X) game, introduced by R. Telgarsky, see [R. Telgarsky, Spaces defined by topological games, Fund. Math. 88 (1975) 193-223], has a winning strategy. The paper contains some results supporting this conjecture.     

Some remarks in iterated function spaces

In this paper we give some new topological cardinal inequalities in iterated function spaces. Open questions are posed.     

Several remarks on dimensions modulo ANR-compacta

We investigate a dimension function L-dim (L is a class of ANR-compacta). Main results are as follows.Let L be an ANR-compactum.(1) If L*L is not contractible, then for every n?0 there is a cube Im with .(2) If L is simply connected and f:X→Y is an acyclic mapping from a finite-dimensional compact Hausdorff space X onto a finite-dimensional space Y, then .(3) If L is simply connected and L*L is not contractible, then for every n?2 there exists a compact Hausdorff space such that , and for an arbitrary closed set either or .     

Some remarks concerning Riemannian extensions

We study some properties of Riemannian extensions in cotangent bundles with the help of adapted frames.     

More remarks on Souslin properties and tree topologies

We investigate separation properties of ω₁-trees. We show that the property γ of Devlin and Shelah is equivalent to hereditary collectionwise normality. We show that monotone normality and divisibility are both equivalent to orderability. Finally we show that Souslin trees are examples of trees with property γ which are not retractable.     

Some characterizations of spaces that have transfinite dimension

We characterize separable metrizable spaces that have small transfinite dimension and metrizable spaces that have large transfinite dimension modifying two classical characterizations of countable-dimensional spaces and applying the notion of a strongly point-finite family.     

Some generalizations of the concept of a p-space

In this article, some generalizations of the concept of a p-space are introduced and studied. The notion of a source of a space in a larger space and the concepts of partial plumage, s-embedding, p-embedding, p^?-embedding, s-space, and p^?-space are defined and studied in depth (see Theorems 2.6, 2.7, 3.2, 4.3, 4.4, 4.10 and their corollaries). An example of a hereditarily p^?-space which is not a p-space and is a perfect image of a hereditarily p-space is indicated (Example 2.9). Among the main results, we establish that if a paracompact space X is p-embedded in a pseudocompact space as a dense subspace, then X is a p-space (Corollary 4.8), and that if X has a countable network and is p^?-embedded in a pseudocompact space, then X is metrizable (Corollary 4.11). The following problem is posed: is every paracompact Gδ-subspace of a pseudocompact space ?ech-complete?     

Some remarks on interior operators and the functional property

In this paper functoriality of the notion of categorical interior operator is discussed and as a related topic, the property of ?-modal interior operator is introduced.     

Some remarks on lengths of propositional proofs

We survey the best known lower bounds on symbols and lines in Frege and extended Frege proofs. We prove that in minimum length sequent calculus proofs, no formula is generated twice or used twice on any single branch of the proof. We prove that the number of distinct subformulas in a minimum length Frege proof is linearly bounded by the number of lines. Depthd Frege proofs ofm lines can be transformed into depthd proofs ofO(m ^d+1) symbols. We show that renaming Frege proof systems are p-equivalent to extended Frege systems. Some open problems in propositional proof length and in logical flow graphs are discussed. Supported in part by NSF grant DMS-9205181     

Some remarks concerning weakly disconjugate linear Hamiltonian systems

We study properties of weakly disconjugate linear Hamiltonian systems. We characterize this concept in terms of a nonoscillation condition. We then show how to approximate a weakly disconjugate system by one with an exponential dichotomy.     

Some remarks concerning the infinite distributivity of lattices

Theorems are proved concerning the regular imbedding of an infinitely distributive lattice in least decomposable lattices and in completely decomposable lattices. A relation is established between decomposable lattices, Stone lattices, and completely decomposable lattices.Translated from Matematicheskie Zametki, Vol. 8, No. 1, pp. 95–103, July, 1970.We use this opportunity to thank A. G. Pinsker for his valuable advice concerning this work.     

Some remarks on a question of Strassen

Summary Strassen's original functional law of the iterated logarithm for partial sums and Brownian motion examined convergence and clustering in the sup-norm. Here we address what happens if we use the much larger H-norm. We provide the answer to a query which appeared at the end of Strassen's original paper, and also present several contrasting results which are shown to be essentially best possible.Supported in part by NSA Grant MDA-904-93-H-3033Supported in part by NSF Grant DMS-9400024     

Some remarks on isologic extensions of groups

In this paper we study the concept of -isologisms among the -marginal extensions of groups, with respect to a given variety of groups . We also give some equivalent conditions under which two extensions are -isologic. Received: 9 January 2002     

Some remarks on hilbert functions of veronese algebras

We study the Hilbert polynomials of finitely generated graded algebras R, with generators not all of degree one (i.e. non-standard). Given an expression P(R,t)=a(t)/(1-t^l ) ⁿ for the Poincare series of R as a rational function, we study for 0 ≤ i ≤ l the graded subspaces ? _kR_kl+i (which we denote R[l;i]) of R, in particular their Poincaré series and Hilbert functions. We prove, for example, that if R is Cohen-Macaulay then the Hilbert polynomials of all non-zeroR[l;i] share a common degree. Furthermore, if R is also a domain then these Hilbert polynomials have the same leading coefficient.     

Some new characterizations of pointfree pseudocompactness

Abstract

By [3], a frame L is pseudocompact iff every ??-sequence in L joining to the top terminates. Here it is shown, for any completely regular L, that pseudocompactness is also equivalent to (i) the analogous condition for ?-sequences, (ii) the countable almost compactness of L, (iii) the almost compactness of CozL as a σ-frame and (iv) the condition that every countably based proper filter in L clusters. Further we establish the zero-dimensional counterparts of the above, concerning the integer valued notion of pseudocompactness. Finally, we add to this a characterization of pseudocompactness in terms of uniformities.