We show that for every we ordered cardinal number m the Tychonoff product 2m is a compact space without the use of any choice but in Cohen's Second Mode 2ℝ is not compact.

Lascar described E KP as a composition of E L and the topological closure of E L (Casanovas et al. in J Math Log 1(2):305–319). We generalize this result to some other pairs of equivalence relations. Motivated by an attempt to construct a new example of a non-G-compact theory, we consider the following example. Assume G is a group definable in a structure M. We define a structure M′ consisting of M and X as two sorts, where X is an (...) affine copy of G and in M′ we have the structure of M and the action of G on X. We prove that the Lascar group of M′ is a semi-direct product of the Lascar group of M and G/G L . We discuss the relationship between G-compactness of M and M′. This example may yield new examples of non-G-compact theories. (shrink)

In this dissertation we explore projective Fraïssé theory and its applications, as well as limitations, to the study of compact metrizable spaces. The goal of projective Fraïssé theory is to approximate spaces via classes of finite structures and glean topological or dynamical properties of a space by relating them to combinatorial features of the associated class of structures. Using the framework of compact metrixable structures, we establish general results which expand and help contextualize previous works in the field. Many proofs (...) in the domain of projective Fraïssé theory are carried out in a context dependent fashion and have thus far eluded clean generalizations. A reason is to be found in the lack of a clear understanding of which spaces are amenable to be studied via projective Fraïssé limits. We give both positive and negative results in this direction. We isolate a combinatorial condition which entails a correspondence between finite structures and regular quasi-partitions of compact metrizable spaces. This correspondence greatly aids the combinatorial-toplogical translation. We apply this machinery to study a class of one-dimensional compact metrizable spaces, which we call smooth fences. To this end, we isolate a class of finite structures—finite partial orders whose Hasse diagram is a forest—whose projective Fraïssé limit approximates a distinctive smooth fence with remarkable properties. We call it the Fraïssé fence and characterize it topologically by carefully exploiting the bridge between the combinatorial and topological worlds. We explore homogeneity and universality features of the Fraïssé fence and the properties of its spaces and endpoints, and provide some results on the dynamics of its group of homeomorphisms. The dissertation is partially based on [1, 2]. (shrink)

We study the isomorphism relation on Borel classes of locally compact Polish metric structures. We prove that isomorphism on such classes is always classifiable by countable structures (equivalently: Borel reducible to graph isomorphism), which implies, in particular, that isometry of locally compact Polish metric spaces is Borel reducible to graph isomorphism. We show that potentially $\boldsymbol {\Pi }^{0}_{\alpha + 1}$ isomorphism relations are Borel reducible to equality on hereditarily countable sets of rank $\alpha $, $\alpha \geq 2$. We also study (...) approximations of the Hjorth-isomorphism game, and formulate a condition ruling out classifiability by countable structures. (shrink)

We continue [2], developing simplicity in the framework of compact abstract theories. Due to the generality of the context we need to introduce definitions which differ somewhat from the ones use in first order theories. With these modified tools we obtain more or less classical behaviour: simplicity is characterized by the existence of a certain notion of independence, stability is characterized by simplicity and bounded multiplicity, and hyperimaginary canonical bases exist.

. From a proper class of supercompact cardinals, we force and obtain a model in which the proper classes of strongly compact and strong cardinals precisely coincide. In this model, it is the case that no strongly compact cardinal \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $\kappa$\end{document} is \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $2^\kappa = \kappa^+$\end{document} supercompact.

This is a continuation of [2]. We study the Tychonoff Compactness Theorem for various definitions of compactness and for various types of spaces . We also study well ordered Tychonoff products and the effect that the multiple choice axiom has on such products.

The history of productivity of the κ-chain condition in partial orders, topological spaces, or Boolean algebras is surveyed, and its connection to the set-theoretic notion of a weakly compact cardinal is highlighted. Then, it is proved that for every regular cardinal κ > א1, the principle □ is equivalent to the existence of a certain strong coloring c : [κ]2 → κ for which the family of fibers T is a nonspecial κ-Aronszajn tree. The theorem follows from an analysis of (...) a new characteristic function for walks on ordinals, and implies in particular that if the κ-chain condition is productive for a given regular cardinal κ > א1, then κ is weakly compact in some inner model of ZFC. This provides a partial converse to the fact that if κ is a weakly compact cardinal, then the κ-chain condition is productive. (shrink)

We show relative to strong hypotheses that patterns of compact cardinals in the universe, where a compact cardinal is one which is either strongly compact or supercompact, can be virtually arbitrary. Specifically, we prove if V “ZFC + Ω is the least inaccessible limit of measurable limits of supercompact cardinals + ƒ : Ω → 2 is a function”, then there is a partial ordering P V so that for , There is a proper class of compact cardinals + If (...) ƒ = 0, then the αth compact cardinal is not supercompact + If ƒ = 1, then the αth compact cardinal is supercompact”. We then prove a generalized version of this theorem assuming κ is a supercompact limit of supercompact cardinals and ƒ : κ → 2 is a function, and we derive as corollaries of the generalized version of the theorem the consistency of the least measurable limit of supercompact cardinals being the same as the least measurable limit of nonsupercompact strongly compact cardinals and the consistency of the least supercompact cardinal being a limit of strongly compact cardinals. (shrink)

I present solutions to several questions of Paul Bankston [2] by means of another version of the ultracoproduct construction, and explain the relation of ultracoproduct of compact Hausdorff spaces to other constructions combining topology, algebra and logic.

We establish the following results: 1. In ZF (i.e., Zermelo-Fraenkel set theory minus the Axiom of Choice AC), for every set I and for every ordinal number α ≥ ω, the following statements are equivalent: (a) The Tychonoff product of| α| many non-empty finite discrete subsets of I is compact. (b) The union of| α| many non-empty finite subsets of I is well orderable. 2. The statement: For every infinite set I, every closed subset of the Tychonoff product [0, 1] (...) I which consists of functions with finite support is compact, is not provable in ZF set theory. 3. The statement: For every set I, the principle of dependent choices relativised to I implies the Tychonoff product of countably many non-empty finite discrete subsets of I is compact, is not provable in ZF⁰ (i.e., ZF minus the Axiom of Regularity). 4. The statement: For every set I, every ℵ₀-sized family of non-empty finite subsets of I has a choice function implies the Tychonoff product of ℵ₀ many non-empty finite discrete subsets of I is compact, is not provable in ZF⁰. (shrink)

We work in set-theory without choice ZF. A set is Countable if it is finite or equipotent with ${\Bbb N}$ . Given a closed subset F of [0, 1] I which is a bounded subset of $\ell ^{1}(I)$ (resp. such that $F\subseteq c_{0}(I)$ ), we show that the countable axiom of choice for finite sets, (resp. the countable axiom of choice AC N ) implies that F is compact. This enhances previous results where AC N (resp. the axiom of Dependent (...) Choices) was required. If I is linearly orderable (for example $I={\Bbb R}$ ), then, in ZF, the closed unit ball of the Hilbert space $\ell ^{2}(I)$ is (Loeb-)compact in the weak topology. However, the weak compactness of the closed unit ball of $\ell ^{2}(\scr{P}({\Bbb R}))$ is not provable in ZF. (shrink)

In recent years, there has been a growing interest in truthmaker semantics as a framework for understanding a range of phenomena in philosophy and linguistics. Despite this interest, there has been limited study of the various logics that arise from the semantics. This paper aims to address this gap by exploring numerous ‘truthmaker logics’ and proving their compactness and decidability. This is in continuation with the inquiry of Fine and Jago (2019), who proved compactness and decidability for a particular kind (...) of truthmaker logic. The key results going into this are (1) ‘standard translations’ into first-order logic; (2) a truthmaker analogue of the finite model property; and (3) a proof showing that truthmaker consequence on semilattices coincides with truthmaker consequence on complete lattices. Finally, the connection with modal logic is examined. Specifically, it is illustrated how endowing truthmaker semantics with classical negation results in modal information logics. (shrink)

THEOREM 1. (⋄ ℵ 1 ) If B is an infinite Boolean algebra (BA), then there is B 1 such that $|\operatorname{Aut} (B_1)| \leq B_1| = \aleph_1$ and $\langle B_1, \operatorname{Aut} (B_1)\rangle \equiv \langle B, \operatorname{Aut}(B)\rangle$ . THEOREM 2. (⋄ ℵ 1 ) There is a countably compact logic stronger than first-order logic even on finite models. This partially answers a question of H. Friedman. These theorems appear in §§ 1 and 2. THEOREM 3. (a) (⋄ ℵ 1 ) If (...) B is an atomic ℵ 1 -saturated infinite BA, ψ ε L ω 1ω and $\langle B, \operatorname{Aut} (B)\rangle \models\psi$ then there is B 1 such that $|\operatorname{Aut}(B_1)| \leq |B_1| = \aleph_1$ and $\langle B_1, \operatorname{Aut}(B_1)\rangle\models\psi$ . In particular if B is 1-homogeneous so is B 1 . (b) (a) holds for B = P(ω) even if we assume only CH. (shrink)

We point out a connection between reflection principles and generic large cardinals. One principle of pure reflection is introduced that is as strong as generic supercompactness of ω2 by Σ-closed forcing. This new concept implies CH and extends the reflection principles for stationary sets in a canonical way.

In recent years, there has been a growing interest in truthmaker semantics as a framework for understanding a range of phenomena in philosophy and linguistics. Despite this interest, there has been limited study of the various logics that arise from the semantics. This paper aims to address this gap by exploring numerous ‘truthmaker logics’ and proving their compactness and decidability. This is in continuation with the inquiry of Fine and Jago (2019), who proved compactness and decidability for a particular kind (...) of truthmaker logic. The key results going into this are (1) ‘standard translations’ into first-order logic; (2) a truthmaker analogue of the finite model property; and (3) a proof showing that truthmaker consequence on semilattices coincides with truthmaker consequence on complete lattices. Finally, the connection with modal logic is examined. Specifically, it is illustrated how endowing truthmaker semantics with classical negation results in modal information logics. (shrink)

A Polish space is not always homeomorphic to a computably presented Polish space. In this article, we examine degrees of non-computability of presenting homeomorphic copies of compact Polish spaces. We show that there exists a $\mathbf {0}'$ -computable low $_3$ compact Polish space which is not homeomorphic to a computable one, and that, for any natural number $n\geq 2$, there exists a Polish space $X_n$ such that exactly the high $_{n}$ -degrees are required to present the homeomorphism type of $X_n$. (...) Along the way we investigate the computable aspects of Čech homology groups. We also show that no compact Polish space has a least presentation with respect to Turing reducibility. (shrink)

It is known that if $\kappa < \lambda$ are such that κ is indestructibly supercompact and λ is 2λ supercompact, then level by level equivalence between strong compactness and supercompactness fails. We prove a theorem which points towards this result being best possible. Specifically, we show that relative to the existence of a supercompact cardinal, there is a model for level by level equivalence between strong compactness and supercompactness containing a supercompact cardinal κ in which κ’s strong compactness is indestructible (...) under κ-directed closed forcing. (shrink)

We prove two theorems concerning indestructibility properties of the first two strongly compact cardinals when these cardinals are in addition the first two measurable cardinals. Starting from two supercompact cardinals $\kappa _1 < \kappa _2$, we force and construct a model in which $\kappa _1$ and $\kappa _2$ are both the first two strongly compact and first two measurable cardinals, $\kappa _1$ ’s strong compactness is fully indestructible, and $\kappa _2$ ’s strong compactness is indestructible under $\mathrm {Add}$ for any (...) ordinal $\delta $. This provides an answer to a strengthened version of a question of Sargsyan found in [17, Question 5]. We also investigate indestructibility properties that may occur when the first two strongly compact cardinals are not only the first two measurable cardinals, but also exhibit nontrivial degrees of supercompactness. (shrink)

We go on along the trend of [2] and [1], giving an axiomatization of S4 0 and proving its completeness and compactness with respect to the usual reflexive and transitive Kripke models. To reach this results, we use techniques from [1], with suitable adaptations to our specific case.

We investigate the covering numbers of some ideals on $${^{\omega }}{2}{}$$ ω 2 associated with tree forcings. We prove that the covering of the Sacks ideal remains small in the Silver and uniform Sacks model, respectively, and that the coverings of the uniform Sacks ideal and the Mycielski ideal, $${\mathfrak {C}_{2}}$$ C 2, remain small in the Sacks model.

The physical meaning of the particularly simple non-degenerate supermetric, introduced in the previous part by the authors, is elucidated and the possible connection with processes of topological origin in high energy physics is analyzed and discussed. New possible mechanism of the localization of the fields in a particular sector of the supermanifold is proposed and the similarity and differences with a 5-dimensional warped model are shown. The relation with gauge theories of supergravity based in the OSP(1/4) group is explicitly given (...) and the possible original action is presented. We also show that in this non-degenerate super-model the physic states, in contrast with the basic states, are observables and can be interpreted as tomographic projections or generalized representations of operators belonging to the metaplectic group Mp(2). The advantage of geometrical formulations based on non-degenerate super-manifolds over degenerate ones is pointed out and the description and the analysis of some interesting aspects of the simplest Riemannian superspaces are presented from the point of view of the possible vacuum solutions. (shrink)

We summarize the known methods of producing a non-supercompact strongly compact cardinal and describe some new variants. Our Main Theorem shows how to apply these methods to many cardinals simultaneously and exactly control which cardinals are supercompact and which are only strongly compact in a forcing extension. Depending upon the method, the surviving non-supercompact strongly compact cardinals can be strong cardinals, have trivial Mitchell rank or even contain a club disjoint from the set of measurable cardinals. These results improve and (...) unify Theorems 1 and 2 of [5], due to the first author. (shrink)

Assuming the existence of a weakly compact hypermeasurable cardinal we prove that in some forcing extension א ω is a strong limit cardinal and א ω+2 has the tree property. This improves a result of Matthew Foreman (see [2]).

In recent years, proof theoretic transformations that are based on extensions of monotone forms of Gödel’s famous functional interpretation have been used systematically to extract new content from proofs in abstract nonlinear analysis. This content consists both in effective quantitative bounds as well as in qualitative uniformity results. One of the main ineffective tools in abstract functional analysis is the use of sequential forms of weak compactness. As we recently verified, the sequential form of weak compactness for bounded closed and (...) convex subsets of an abstract Hilbert space can be carried out in suitable formal systems that are covered by existing metatheorems developed in the course of the proof mining program. In particular, it follows that the monotone functional interpretation of this weak compactness principle can be realized by a functional Ω∗ definable from bar recursion of lowest type. While a case study on the analysis of strong convergence results that are based on weak compactness indicates that the use of the latter seems to be eliminable, things apparently are different for weak convergence theorems such as the famous Baillon nonlinear ergodic theorem. For this theorem we recently extracted an explicit bound on a metastable version of this theorem that is primitive recursive relative to Ω∗.In the current paper we for the first time give the construction of Ω∗ . As a corollary to the fine analysis of the use of bar recursion in this construction we obtain that Ω∗ elevates arguments in Tn at most to resulting functionals in Tn+2 . In particular, one can conclude from this that our bound on Baillon’s theorem is at least definable in T4. (shrink)

Angelaki, Volume 17, Issue 2, Page 31-48, June 2012.

The corporate citizenship (CC) concept introduced by Dirk Matten and Andrew Crane has been well received. To this date, however, empirical studies based on this concept are lacking. In this article, we flesh out and operationalize the CC concept and develop an assessment tool for CC. Our tool focuses on the organizational level and assesses the embeddedness of CC in organizational structures and procedures. To illustrate the applicability of the tool, we assess five Swiss companies (ABB, Credit Suisse, Nestlé, Novartis, (...) and UBS). These five companies are participants of the UN Global Compact (UNGC), currently the largest collaborative strategic policy initiative for business in the world (www.unglobalcompact.org). This study makes four main contributions: (1) it enriches and operationalizes Matten and Crane’s CC definition to build a concept of CC that can be operationalized, (2) it develops an analytical tool to assess the organizational embeddedness of CC, (3) it generates empirical insights into how five multinational corporations have approached CC, and (4) it presents assessment results that provide indications how global governance initiatives like the UNGC can support the implementation of CC. (shrink)

We show that the tree property, stationary reflection and the failure of approachability at \ are consistent with \= \kappa ^+ < 2^\kappa \), where \ is a singular strong limit cardinal with the countable or uncountable cofinality. As a by-product, we show that if \ is a regular cardinal, then stationary reflection at \ is indestructible under all \-cc forcings.

We discuss the existence of universal spaces (either in the sense of embeddings or continuous images) for some classes of scattered Eberlein compacta. Given a cardinal κ, we consider the class Sκ of all scattered Eberlein compact spaces K of weight ≤ κ and such that the second Cantor-Bendixson derivative of K is a singleton. We prove that if κ is an uncountable cardinal such that κ = 2<κ, then there exists a space X in Sκ such that every member (...) of Sκ is homeomorphic to a retract of X. We show that it is consistent that there does not exist a universal space (either by embeddings or by mappings onto) in Sω₁. Assuming that ∂ = ω₁, we prove that there exists a space X ∈ Sω₁, which is universal in the sense of embeddings. We also show that it is consistent that there exists a space X ∈ Sω₁, universal in the sense of embeddings, but Sω₁ does not contain an universal element in the sense of mappings onto. (shrink)

We propose developing the theory of consequences of morasses relevant in mathematical applications in the language alternative to the usual one, replacing commonly used structures by families of sets originating with Velleman’s neat simplified morasses called 2-cardinals. The theory of related trees, gaps, colorings of pairs and forcing notions is reformulated and sketched from a unifying point of view with the focus on the applicability to constructions of mathematical structures like Boolean algebras, Banach spaces or compact spaces. The paper is (...) dedicated to the memory of Jim Baumgartner whose seminal joint paper :109–129, 1987) with Saharon Shelah provided a critical mass in the theory in question. A new result which we obtain as a side product is the consistency of the existence of a function \ with the appropriate \-version of property \ for regular \ satisfying \. (shrink)

Assuming the existence of a supercompact cardinal and a weakly compact cardinal above it, we provide a generic extension where there are no Aronszajn trees of height ω 2 or ω 3 . On the other hand we show that some large cardinal assumptions are necessary for such a consistency result.

The Dirac operator arises naturally on $\mathbb{S}^1 \times \mathbb{S}^3 $ from the connection on the Lie group U(1)×SU(2) and maps spacetime rays into rays in the Lie algebra. We construct both simple harmonic and pulse solutions to the neutrino equations on $\mathbb{S}^1 \times \mathbb{S}^3 $ , classified by helicity and holonomy, using this map. Helicity is interpreted as the internal part of the Noether charge that arises from translation invariance; it is topologically quantized in integral multiples of a constant g (...) that converts a Lie-algebra phase shift into an action. The fundamental unit of helicity is associated with a full twist in u(1)×su(2) phase per global lightlike cycle. If we pass to the projective space ℝP1xℝP3, we get half-integral helicity. (shrink)

This book summarizes in a compact volume Runciman’s arguments to comparative sociologists that their discipline belongs under the theoretical umbrella of neo-Darwinian selectionism. In his view, heritable variation and competitive selection govern cultural and social as well as biological evolution. Runciman makes a strong case for the usefulness of selectionism, but two of the theory’s central features are problematic: his choice of units of selection; and the notion that culture can be distinguished from society historically as well as analytically. No (...) one friendly to the basic project would argue against the need for hypotheses about units that undergo selection, but arguments can be made, also on pragmatic grounds, that he has chosen the wrong kinds of units. Runciman’s learning and wisdom show to good effect in the book’s fundamental approach: in the overall human story, the biological, cultural, and social coevolve. The quickly accumulating evidence of evolutionary psychology, anthropology, sociology, and neuroscience strongly supports the hypothesis that there is a biological basis for a great deal of human behavior, and also that sociocultural evolution modifies genes. History, in this way of thinking, is like a “braided stream” of unpredictably mutating, blending, and coevolving biological, cultural, and social processes. The old Darwinian image of branching fails to capture the complexity of evolutionary processes in biology, culture, and society. Runciman outlines a unified bio-social science relying upon information theory. If his program were carried out consistently it would relegate to a non-scientific level the traditional historical narratives about “carriers” or “vehicles.” The scientific-explanatory level would instead feature replicators. Game-theory strategies play a prominent role in the selectionist picture. The emphasis on units of information stored in human brains or in exosomatic brain prostheses pushes neuroscience and information theory to the fore. An argument for the analytic-heuristic value of “memes” and “practices” should be weighed against the value of other hypothetical units undergoing selection in a sociocultural evolutionary approach. (shrink)

In this paper, we provide a detailed review of previous classifications of 2 × 2 games and suggest a mathematically simple way to classify the symmetric 2 × 2 games based on a decomposition of the payoff matrix into a cooperative and a zero-sum part. We argue that differences in the interaction between the parts is what makes games interesting in different ways. Our claim is supported by evolutionary computer experiments and findings in previous literature. In addition, we provide a (...) method for using a stereographic projection to create a compact 2-d representation of the game space. (shrink)

Context: In this paper I expand aspects of the generalized bottom-up explanatory approach devised in Part I to expound the natural emergence of composite self-organized dynamic systems endowed with self-produced embodied boundaries and with observed degrees of autonomous behavior. In Part I, the focus was on the rules defined by Varela, Maturana & Uribe (VM&U rules), viewed as a validation test to assess if an observed system is autopoietic. This was accomplished by referring to Maturana’s ontological-epistemological frame and by defining (...) distinctions, concepts, and abstractions necessary to describe dynamic systems in any observational domain. This approach concentrates on pure causation flow rather than on domain-specific interaction mechanisms. Problem: It is essential to analyze the requirements imposed by the VM&U rules on the “intra-boundaries” phenomenology for compliance with the self-production capabilities expected from an autopoietic system. Beyond what is merely implied by the compact wording of the VM&U rules, a key point needs to be addressed explicitly: how to describe some “peculiar” capabilities that the components should be endowed with to participate in new component production (as macro-molecules do in the biological domain) so that system’s self-production can be assessed. Method: Using this approach, I first describe the process of constituting self-organized dynamic structures provided with embodied boundaries. Then I explain how a capability of self-organization emerges and how this results in ephemeral configurations that may evolve into self-regulated long-lasting dynamic system stability within a continuous causation flow inside the boundaries, up to the emergence of some “specialized” subsets of components. This explication allows us to distinguish the medium, the boundaries, and the core of a self-organized dynamic system and to focus attention on the “intra-boundaries” phenomenology that should be at the heart of self-production capabilities, as prescribed by the 5th and 6th VM&U rules. Results: I propose an abstract, domain-free description of the “peculiar” composition and decomposition transformation capabilities that components should possess while subject to state transitions triggered within the “intra-boundaries” causation flow. This is combined with a discussion concerning the “intra-boundaries” causation structure’s possible topological layouts that could be compliant with the 6th rule. Implications: The above-mentioned results allow us to improve our analytic criteria when observing dynamic systems existing in non-biological domains in order to assess their autopoietic nature. They also reveal that the task of consistently identifying possible non-biological autopoietic systems is harder than merely identifying self-organized dynamic systems provided with boundaries and some observable autonomous behavioral capabilities in a given observational domain. More implications will be discussed further in Part III. (shrink)

In this paper, it is shown that if [Formula: see text] is a complete type of Lascar rank at least 2, in the theory of differentially closed fields of characteristic zero, then there exists a pair of realisations [Formula: see text], [Formula: see text] such that p has a nonalgebraic forking extension over [Formula: see text]. Moreover, if A is contained in the field of constants then p already has a nonalgebraic forking extension over [Formula: see text]. The results are (...) also formulated in a more general setting. (shrink)

The iconic status of the periodic table of the elements has been recognized by a variety of prominent chemists and historians of science. For example, John Emsley proclaimed: “As long as chemistry is studied there will be a periodic table. And even if someday we communicate with another part of the universe, we can be sure that one thing that both cultures will have in common is an ordered system of the elements that will be instantly recognizable by both intelligent (...) life forms” .Furthermore, its paramount significance is universally recognized even far beyond the field of chemistry. According to the late American astronomer Harlow Shapley , “[The periodic table] is probably the most compact and meaningful compilation of knowledge that man has yet devised. The periodic table does for matter what the geological age table does for cosmic time. Its history is the story of man’s great conquests in the microcosmos” .Of course, philosopher of science Eri .. (shrink)

Assume ZFC + "There is a weakly compact cardinal" is consistent. Then: For every $S \subseteq \omega, \mathrm{ZFC} +$ "S and the monadic theory of ω 2 are recursive each in the other" is consistent; and ZFC + "The full second-order theory of ω 2 is interpretable in the monadic theory of ω 2 " is consistent.

We prove the iteration lemmata, which are the key lemmata to show that extensions by Pmax variations satisfy absoluteness for Π2-statements in the structure 〈H , ∈, NSω 1, R 〉 for some set R of reals in L , for the following statements: The cofinality of the null ideal is ℵ1. There exists a good basis of the strong measure zero ideal.

We define the property of Π2-compactness of a statement Φ of set theory, meaning roughly that the hard core of the impact of Φ on combinatorics of 1 can be isolated in a canonical model for the statement Φ. We show that the following statements are Π2-compact: “dominating NUMBER = 1,” “cofinality of the meager IDEAL = 1”, “cofinality of the null IDEAL = 1”, “bounding NUMBER = 1”, existence of various types of Souslin trees and variations on uniformity of (...) measure and CATEGORY = 1. Several important new metamathematical patterns among classical statements of set theory are pointed out. (shrink)

We show that strongly compact cardinals and MM are sensitive to $\lambda$-closed forcings for arbitrarily large $\lambda$. This is done by adding ‘regressive' $\lambda$-Kurepa trees in either case. We argue that the destruction of regressive Kurepa trees requires a non-standard application of MM. As a corollary, we find a consistent example of an $\omega_2$-closed poset that is not forcing equivalent to any $\omega_2$-directed-closed poset.

continent. 2.2 (2012): 148–151 When things get complex, as they may indeed be getting, the distinction between tools and the things that can be made with them begins to dissolve. The medium is not only also a message, it is an essential counter-valence to our own impulses towards the creation of meaning, beauty and knowledge. The tools we think we are using also use us: They push us around, make us think new things, do new things, even be new things. (...) Language is no different, of course, although in its supremacy and ubiquity, it is even more elusive, difficult to perceive. The very words you are looking at right now are like compact little cryptograms—a written convention, talking back at you in codes. Poetry is language speaking for itself. It is, at its best, where what is being told is coincident with the telling. The words written, or uttered, pop out at us, while in the same moment, constellations of meaning emerge; the components and its composition resonate, vacillate, on the page and in the air. Many of the constraints and styles of poetry we know have developed in order to allow words to express themselves, or show themselves as the mediation of a mental image. Programming languages for computer hardware, no matter how “high level” or abstract they are, are by necessity far less elaborate than traditional forms of writing and speech. But the structure and function of these new languages give them special advantage in clarity: These languages (syntax, sequence) and the results they produce (ideas, ‘executables’) are absolutely inseparable. By design, computing languages are created in order to express specific ideas, creating certain kinds of action or manipulation of other codes (data). In this sense perhaps, software is always, and already, poetic. It is precise description, and pure syntax—the signifier and signified—clearly coincident in the machine. Ishac Bertran ’s code {poems} is an edited book project that exposes the materiality of computer programming languages. Here are presented a small sampling from a compiled book of poetry written by software engineers, artists and other code writers, “exploring the potential of code to communicate at the level of poetry.” ( code-poems.com ) The project solicited for online, public submissions from code-writers in response to the notion of a poem, written in a software language which is semantically valid (i.e.: it compiles ). This solicitation winds up revealing the inner workings, constitutive elements, and styles of both a particular software and its authors. From a large number of submissions, a selection of poems will be printed as a bound volume in the Autumn of 2012. - Jamie Allen __________________________________________________ DAILYGRIND import java.util.Date; public class DailyGrind { public static final void main(String[] args) { boolean its_time_to_go_home = false; boolean away_the_hours = true; while (away_the_hours) { boolean away_the_hours = true; Date now = new Date(); its_time_to_go_home = now.getHours() > 17 && now.getMinutes() > 30; if (its_time_to_go_home) { break; } try { Thread.sleep(60000); } catch (InterruptedException e) { // ignore } } } } Paul Illingworth // Java __________________________________________________ UNHANDLED LOVE class love {}; void main() { throw love(); } Daniel Bezerra // C++ __________________________________________________ TWOFACED public class TwoFaced { public String greet() { return "Hi! So great to see you!"; } private String think() { return "Fucking bitch."; } } Jason Kopylec // Java __________________________________________________ DANCING WITHIN using System; public class PoemCode { private bool dancing_within() { Boolean me = true; while (dancing_within()) { var iables_of_light = ""; try { int elligently_to; object ify_the_world_apart; } catch (Exception s) { int o_the_broken_parts; throw; int o_the_seed_of_life; } Random ashes_of = new Random(); float ing_devices; short age_of; char acter_will_never_let_you = 'b'; } return me; } } Álvaro Matías Wong Díaz // C#  . (shrink)

Regulatory schema has shifted from government to governance-based systems. One particular form that has emerged at the international level is the multi-stakeholder voluntary code of conduct (MSVC). We argue that such codes are not only simply mechanisms by which various stakeholders attempt to govern the action of the corporation but also systems by which each stakeholder attempts to gain or retain some legitimacy goal. Each stakeholder is motivated by strategic legitimacy goal to join the code, and once a member, is (...) also required to assist in maintaining the institutional legitimacy of the code, resulting in “networked legitimacy.” We begin our analysis of these systems by first exploring the growth and structure of such MSVCs, and then building an analytical framework using strategic and institutional legitimacy as they apply to such MSVCs. We contribute to the codes of conduct literature by developing the construct of networked legitimacy from strategic and institutional legitimacy. We then apply our framework to the United Nations Global Compact, one of the predominant MSVCs today. In doing so, we: (1) demonstrate how different stakeholders are pursuing different types of legitimacy through their participation in the code, (2) examine the specific opportunities and risks in terms of what we have called “networked legitimacy” posed by the institutional design of actual MSVCs, and (3) create an argument for three pillars supporting the legitimacy of MSVCs. (shrink)

This compact volume, belonging to the Cambridge Elements series, is a useful introduction to some of the most fundamental questions of philosophy and foundations of mathematics. What really distinguishes realist and platonist views of mathematics from anti-platonist views, including fictionalist and nominalist and modal-structuralist views?1 They seem to confront similar problems of justification, presenting tradeoffs between which it is difficult to adjudicate. For example, how do we gain access to the abstract posits of platonist accounts of arithmetic, analysis, geometry, etc., (...) including numbers, functions, sets, points, lines, spaces, etc., whether it be such objects themselves or the possibilities of such, as postulated by modal and modal structural accounts?2 What real difference does it make, whether it be the existence of such things or the mathematical possibility of such things? Even fictionalist views seem to confront analogous problems. After all, we rely on mathematics for myriad scientific applications; so such mathematics had better at least be coherent, even if not true. But coherence requires at least formal consistency; so we seem implicitly to be committed to things like formal derivations, viz. the absence of any such having contradictory consequences, framed within the appropriate system of axioms and rules. But derivations are themselves akin to mathematical objects, as derivations are strings of strings of symbols. Moreover, derivations provided by axioms and rules form an infinite class, such that, at any future time, infinitely many will not have been written down. Moreover, such strings, as Gödel famously showed, can be coded as natural numbers. Thus, even fictionalist accounts (such as that of Field in his Science without Numbers [2016]) seem to confront problems very much like those plaguing platonist accounts. (shrink)