Recursion in Partial Type-1 Objects With Well-Behaved Oracles

We refine the definition of II-computability of [12] so that oracles have a “consistent”, but natural, behaviour. We prove a Kleene Normal Form Theorem and closure of semi-recursive relations under ?¹. We also show that in this more inclusive computation theory Post's theorem in the arithmetical hierarchy still holds. Mathematics Subject Classification: 03D65, 03D75.     

A generalized Nash equilibrium problem arising in banking regulation: An existence result with Tarski's theorem

When hit with an adverse shock, banks that do not comply with capital regulation sell risky assets to satisfy their solvency constraint. When financial markets are imperfectly competitive, this naturally gives rise to a GNEP. We consider a new framework with an arbitrary number of banks and assets, and show that Tarski's theorem can be used to prove the existence of a Nash equilibrium when markets are sufficiently competitive. We also prove the existence of ?-Nash equilibria.     

Boolos‐style proofs of limitative theorems

Boolos's proof of incompleteness is extended straightforwardly to yield simple “diagonalization‐free” proofs of some classical limitative theorems of logic. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Arithmetical Identities in a 2‐element Model of Tarski's System

All arithmetical identities involving 1, addition, multiplication and exponentiation will be true in a 2‐element model of Tarski's system if a certain sequence of natural numbers is not bounded. That sequence can be bounded only if the set of Fermat's prime numbers is finite.     

微分达布(Darboux)定理的几种新证法及其推广

本文给出了微分达布定理的两种新证法并对其作了推广 .讨论了达布定理及本文推广的达布定理的应用 .     

Some new mean value theorems of Flett type

In this paper, we give some new mean value theorems, which are generalizations of Flett, Myers and Tong's theorems.     

On the Asymptotic Expansion of Hadamard Products

We consider functions f and g which are holomoxphic on closed sectors in C where they admit an asymptotic representation at ∞ in the form of power series in z^-1. We give a simple geometrical condition under which the Hadamard product f*g of f and g porsesses again an asymp totic expansion at ∞. It turns out that the asymptotic expansion of f*g is essentially the formal Hsdamd product of the asymptotic expansions of f and g. Our result yields a slight generaliestion of a well known theorem of W. B. Ford.     

A variant of Hardy's and Miyachi's theorems for the Bessel–Struve transform

In this paper, we establish new versions of Hardy's and Miyachi's theorems for the Bessel–Struve transform.     

Some More Conservation Results on the Baire Category Theorem

In this paper, we generalize a result of Brown and Simpson [1] to prove that RCA₀+Π⁰_∞‐BCT is conservative over RCA₀ with respect to the set of formulae in the form ∃!Xφ(X), where φ is arithmetical. We also consider the conservation of Π⁰_0∞‐BCT over Σ^b₁‐NIA+∇^b₁‐CA.     

Proofs of two conjectures on Catalan triangle numbers

We prove two conjectures on sums of products of Catalan triangle numbers, which were originally conjectured by Miana et al. [Discrete Math. 340 (2017), 2388–2397]. The first one is proved by using Zeilberger's algorithm, and the second one is proved by establishing its q-analogue.     

Characterization of the Relations in Grzegorczyk's Hierarchy Revisited

In his 1953's paper, Grzegorczyk proved that a certain kind of relation classes of Grzegorczyk's hierarchy could be characterized inductively. We give a simpler version of this characterization.     

A Generalization of a Theorem of Birch

We generalize a theorem of Birch on solving systems of homogeneous equations of odd degree to the case of solving systems of homogeneous equations of degree not divisible by a fixed integer s ≥ 2. Birch's theorem is the case s = 2. In addition, we give a new exposition of the proof of Brauer's theorem on solving systems of homogeneous equations.     

微分学中不等式的证明

针对微分学不等式列出五种常用证明方法,即利用单调性证明法,利用拉格朗日中值定理证明法,利用最值证明法,利用泰勒公式证明法,和利用凹凸性证明法.实例说明每种方法的使用细节,以达到使初学者能尽快掌握微分学不等式证明的目的.