The aim of this paper is to prove that for there exist a chain in the Rudin-Frolík order of $βκ\setminus κ$ of length $μ$ with $κ\leqslant μ\leqslant 2^κ$ for regular $κ> ω$ without a lower bound.
En el presente artículo expongo los resultados de una investigación etnográfica basada en observaciones y entrevistas sobre la disputada patrimonialización de Barrio Suárez Mujica en Santiago de Chile, en el marco de las luchas vecinales por la protección de los entornos residenciales, en respuesta a los procesos de densificación de la ciudad neoliberal. Mediante un análisis desde la productividad del conflicto patrimonial en términos territoriales, jurídicos y políticos, concluyo que el entrelazamiento del patrimonio con el componente barrial deriva en un doble proceso de reconstitución y fragmentación del tejido vecinal, que genera nuevas territorialidades y al mismo tiempo produce tensiones debido a las consecuencias jurídicas de la patrimonializacióno. Finalmente, destaco el desarrollo de las aptitudes políticas de los habitantes como reacción a las disposiciones gubernamentales frente a la patrimonialización comunitaria.
We introduce the forcing property "almost strong properness" which sits between properness and strong properness. As an application, we introduce a simple forcing with finite conditions to force $\rm MRP$.
We prove that no infinite field is interpretable in the first-order theory of nonabelian free groups. We also obtain a characterization of Abelian groups interpretable in this theory.
La obra de la escritora mexicana Amparo Dávila (1928) ha sido leída y estudiada de manera intermitente durante los últimos sesenta años. Gracias a la edición del Fondo de Cultura Económica de sus Cuentos reunidos, de 2009, la autora zacatecana ha obtenido nuevos lectores. Asimismo, durante la última década la crítica nacional e internacional se ha interesado nuevamente por su narrativa. No obstante, poco se ha explorado el vínculo entre sus relatos y la filosofía. Este trabajo propone establecer un diálogo entre “Fragmento de un diario”, uno de los cuentos que conforman Tiempo destrozado (1959), y la filosofía de Immanuel Kant, Longino y Eugenio Trías en torno a lo bello, lo sublime y lo siniestro, considerando también las aportaciones de Sigmund Freud acerca de lo ominoso.
We show that the standard Gödel modal logics, as initially introduced by Caicedo and Rodriguez in \cite{CR2009,CR2010}, are not realized by the basic Gödel justification logics although being related by the forgetful projection.
We prove that the problem of determining whether a finite logical matrix determines an algebraizable logic is complete for EXPTIME. The same result holds for the classes of order algebraizable, weakly algebraizable, equivalential and protoalgebraic logics. Finally, the same problem for the class of truth-equational logic is shown to be hard for EXPTIME.
We study clockability for Ordinal Turing Machines (OTMs). In particular, we show that, in contrast to the situation for ITTMs, admissible ordinals can be OTM-clockable, that $Σ_{2}$-admissible ordinals are never OTM-clockable and that gaps in the OTM-clockable ordinals are always started by admissible limits of admissible ordinals.
In this paper, without the axiom of choice, we show that if a certain downward Löwenheim-Skolem property holds then all grounds are uniformly definable. We also prove that the axiom of choice is forceable if and only if the universe is a small extension of some transitive model of $\mathsf{ZFC}$.
Given a Fraïssé class $\mathcal{K}$ and an infinite cardinal $κ,$ we define a forcing notion which adds a structure of size $κ$ using elements of $\mathcal{K}$, which extends the Fraïssé construction in the case $κ=ω.$
Brouwer's fan theorem states that every bar is a uniform bar. We give an overview of the status of this axiom in Bishop's constructive mathematics. In particular, we describe the relationship between the fan theorem, the weak König lemma, and the uniform continuity theorem.
We characterize all ordered Abelian groups whose first order theory in the language {+,<} is strongly dependent. The main result of this note was obtained independently by Halevi-Hasson and Farré.
Consider two paths $f,g:[0;1]\to [0;1]^2$ on the unit square such that $f(0)=(0,0)$, $f(1)=(1,1)$, $g(0)=(0,1)$, $g(1)=(1,0)$, $f(0;1)\subseteq (0;1)^2$ and $g(0;1)\subseteq (0;1)^2$. By continuity of $f$ and $g$ there is a point of intersection. We prove that there is a computable point of intersection if the paths are computable.
We investigate combinations of structures by families of structures relative to families of unary predicates and equivalence relations. Conditions preserving $ω$-categoricity and Ehrenfeuchtness under these combinations are characterized. The notions of $e$-spectra are introduced and possibilities for $e$-spectra are described.
We introduce a notion of valued module which is suitable to study valued fields of positive characteristic. Then we built-up a robust theory of henselianity in the language of valued modules and prove Ax-Kochen Ershov type results.
Scanlon [5] proves Ax-Kochen-Ershov type results for differential-henselian monotone valued differential fields with many constants. We show how to get rid of the condition "with many constants".
Let $p$ be a prime. In this paper we give a proof of the followingresult: A valued field $(K,v)$ of characteristic $p \textgreater{} 0$ is$p$-henselian if and only if every element of strictly positivevaluation if of the form $x^p - x$ for some $x \in K$.
We construct two computable topologically conjugate functions for which no conjugacy is computable, or even hyperarithmetic, resolving an open question of Kennedy and Stockman.