私募真相

一直以来,相对于“私人理财”的热闹,“企业理财”市场则略显沉闷。有业内人士介绍,造成这种局面一方面由于很多企业抱着“多一事不如少一事”的态度,使得相当一部分企业的闲置资金趴在账户上“睡觉”;而另一方面,目前公司理财的产品多是以固定收益类产品为主,投资回报与定期存款相差不大,波澜不惊的业绩回报让企业没有太强投资冲动。     

The slingshot argument and the correspondence theory of truth

The correspondence theory of truth holds that each true sentence corresponds to a discrete fact. Donald Davidson and others have argued (using an argument that has come to be known as the slingshot) that this theory is mistaken, since all true sentences correspond to the same “Great Fact.” The argument is designed to show that by substituting logically equivalent sentences and coreferring terms for each other in the context of sentences of the form ‘P corresponds to the fact that P’ every true sentence can be shown to correspond to the same facts as every other true sentence. The claim is that all substitution of logically equivalent sentences and coreferring terms takes place salva veritate. I argue that the substitution of coreferring terms in this context need not preserve truth. The slingshot fails to refute the correspondence theory.     

The case for an interval-based representation of linguistic truth

This paper develops an interval-based approach to the concept of linguistic truth. A special-purpose interval logic is defined, and it is argued that, for many applications, this logic provides a potentially useful alternative to the conventional fuzzy logic.The key idea is to interpret the numerical truth value v(p) of a proposition p as a degree of belief in the logical certainty of p, in which case p is regarded as true, for example, if v(p) falls within a certain range, say, the interval [0.7, 1]. This leads to a logic which, although being only a special case of fuzzy logic, appears to be no less linguistically correct and at the same time offers definite advantages in terms of mathematical simplicity and computational speed.It is also shown that this same interval logic can be generalized to a lattice-based logic having the capacity to accommodate propositions p which employ fuzzy predicates of type 2.     

Proof interpretations with truth

This article systematically investigates so‐called “truth variants” of several functional interpretations. We start by showing a close relation between two variants of modified realizability, namely modified realizability with truth and q‐modified realizability. Both variants are shown tobe derived from a single “functional interpretation with truth” of intuitionistic linear logic. This analysis suggests that several functional interpretations have truth and q‐variants. These variants, however, require a more involved modification than the ones previously considered. Following this lead we present truth and q‐variants of the Diller‐Nahm interpretation, the bounded modified realizability and the bounded functional interpretation (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Never lie against truth

This is a short tribute to Aleksandr A. Borovkov on the occasion of his 80th birthday.     

The disjunction and existence properties for axiomatic systems of truth

In a language for arithmetic with a predicate T(x), intended to mean “x is the Gödel number of a true sentence”, a set S of axioms and rules of inference has the truth disjunction property if whenever S ⊢ T(\s#A) ∨ T(\s#B), either S ⊢ T(\s#A) or S ⊢ T(\s#B). Similarly, S has the truth existence property if whenever S ⊢ ∃χ T(\s#A(χ)), there is some n such that S ⊢ T(\s#A(n)). Continuing previous work, we establish whether these properties hold or fail for a large collection of possible axiomatic systems.     

A feasible theory of truth over combinatory algebra

We define an applicative theory of truth _TPT${\mathsf{T}}_{\mathsf{PT}}$ which proves totality exactly for the polynomial time computable functions. _TPT${\mathsf{T}}_{\mathsf{PT}}$ has natural and simple axioms since nearly all its truth axioms are standard for truth theories over an applicative framework. The only exception is the axiom dealing with the word predicate. The truth predicate can only reflect elementhood in the words for terms that have smaller length than a given word. This makes it possible to achieve the very low proof-theoretic strength. Truth induction can be allowed without any constraints. For these reasons the system _TPT${\mathsf{T}}_{\mathsf{PT}}$ has the high expressive power one expects from truth theories. It allows embeddings of feasible systems of explicit mathematics and bounded arithmetic.     

An ordinal analysis for theories of self-referential truth

The first attempt at a systematic approach to axiomatic theories of truth was undertaken by Friedman and Sheard (Ann Pure Appl Log 33:1–21, 1987). There twelve principles consisting of axioms, axiom schemata and rules of inference, each embodying a reasonable property of truth were isolated for study. Working with a base theory of truth conservative over PA, Friedman and Sheard raised the following questions. Which subsets of the Optional Axioms are consistent over the base theory? What are the proof-theoretic strengths of the consistent theories? The first question was answered completely by Friedman and Sheard; all subsets of the Optional Axioms were classified as either consistent or inconsistent giving rise to nine maximal consistent theories of truth.They also determined the proof-theoretic strength of two subsets of the Optional Axioms. The aim of this paper is to continue the work begun by Friedman and Sheard. We will establish the proof-theoretic strength of all the remaining seven theories and relate their arithmetic part to well-known theories ranging from PA to the theory of ${\Sigma^1_1}The first attempt at a systematic approach to axiomatic theories of truth was undertaken by Friedman and Sheard (Ann Pure Appl Log 33:1–21, 1987). There twelve principles consisting of axioms, axiom schemata and rules of inference, each embodying a reasonable property of truth were isolated for study. Working with a base theory of truth conservative over PA, Friedman and Sheard raised the following questions. Which subsets of the Optional Axioms are consistent over the base theory? What are the proof-theoretic strengths of the consistent theories? The first question was answered completely by Friedman and Sheard; all subsets of the Optional Axioms were classified as either consistent or inconsistent giving rise to nine maximal consistent theories of truth.They also determined the proof-theoretic strength of two subsets of the Optional Axioms. The aim of this paper is to continue the work begun by Friedman and Sheard. We will establish the proof-theoretic strength of all the remaining seven theories and relate their arithmetic part to well-known theories ranging from PA to the theory of S¹₁{\Sigma^1_1} dependent choice.     

A new concept of predicative truth and definability

In this paper a conception of predicative truth in the language of naive analysis is given, and the peculiarities of the induced logic are studied. It is shown that this concept can be formalized in a system with a constructive Carnap rule and that in a theory based on this concept of truth the same things can be expressed that can be expressed in the usual theories of hyperarithmetic and ramified analysis.Translated from Matematicheskie Zametki, Vol. 13, No. 5, pp. 735–745, May, 1973.     

Local collection and end-extensions of models of compositional truth

We introduce a principle of local collection for compositional truth predicates and show that it is arithmetically conservative over the classically compositional theory of truth. This axiom states that upon restriction to formulae of any syntactic complexity, the resulting predicate satisfies full collection. In particular, arguments using collection for the truth predicate applied to sentences occurring in any given (code of a) proof do not suffice to show that the conclusion of that proof is true, in stark contrast to the case of the induction scheme.We analyse various further results concerning end-extensions of models of compositional truth and the collection scheme for the compositional truth predicate.     

Difference operators and extended truth vectors for discrete functions

Discrete functions are mappings ? of a finite set $\text{d}\text{}$ into a lattice $\text{L}$. Prime blocks and prime antiblocks generalize for discrete functions the well known concepts of prime implicants and of prime implicates for Boolean functions. A lattice difference operator is defined for discrete functions which, together with the concept of extended vector, allows us to derive new attractive algorithms for obtaining the prime blocks and antiblocks of a discrete function. Applications of the theory to p-symmetric Boolean functions and to transient analysis of binary switching networks are mentioned.     

Hypersimplicity and semicomputability in the weak truth table degrees

We study the classes of hypersimple and semicomputable sets as well as their intersection in the weak truth table degrees. We construct degrees that are not bounded by hypersimple degrees outside any non-trivial upper cone of Turing degrees and show that the hypersimple-free c.e. wtt degrees are downwards dense in the c.e. wtt degrees. We also show that there is no maximal (w.r.t. ≤_wtt) hypersimple wtt degree. Moreover, we consider the sets that are both hypersimple and semicomputable, characterize them as the (bi-infinite) c.e. cuts of computable orderings of ℕ of order type ω+ω* and study their wtt degrees. We show that there are hypersimple degrees that are not bounded by any hypersimple semicomputable degree, investigate relationships with the join and look for maximal and minimal elements of related classes. I wish to thank the anonymous referee for making helpful remarks that have improved the presentation of this work.     

Inconsistency as qualified truth: A probability logic approach

We treat the sentences in a finite inconsistent knowledge base as assertions that are true with probability at least some primary threshold η and consider as consequences those assertions entailed to have probability at least some secondary threshold ζ.     

Theory of truth degrees of propositions in two-valued logic

By means of infinite product of evenly distributed probabilistic spaces of cardinal 2 this paper introduces the concepts of truth degrees of formulas and similarity degrees among formulas, and a pseudo-metric on the set of formulas is derived therefrom, this offers a possible framework for developing an approximate reasoning theory of propositions in two-valued logic.