A new method for undecidability proofs of first order theories

A New Method for Undecidability Proofs of First Order Theories

We claim that the reduction of Post's Correspondence Problem to the decision problem of a theory provides a useful tool for proving undecidability of rst order theories given by some interpretation. The goal of this paper is to deene a framework for such reduction proofs. The method proposed is illustrated by proving the undecidability of the theory of a term algebra modulo the axioms of associ...

A New Notion of Cardinality for Countable First Order Theories

We define and investigate HC-forcing invariant formulas of set theory, whose interpretations in the hereditarily countable sets are well behaved under forcing extensions. This leads naturally to a notion of cardinality ||Φ|| for sentences Φ of Lω1,ω, which counts the number of sentences of L∞,ω that, in some forcing extension, become a canonical Scott sentence of a model of Φ. We show this card...

A method for solving first order fuzzy differential equation

First-Order Proofs for Higher-Order Languages

We study the use of the-calculus for semantical descriptions of higher-order concurrent languages with state. As an example, we choose Concurrent Idealized ALGOL (CIA). CIA is particularly interesting as, yet being a core language, it combines imperative and parallel features with a procedural mechanism of full higher order. It can thus be used as a formal model for concurrent programs as, e.g....

solution of security constrained unit commitment problem by a new multi-objective optimization method

چکیده-پخش بار بهینه به عنوان یکی از ابزار زیر بنایی برای تحلیل سیستم های قدرت پیچیده ،برای مدت طولانی مورد بررسی قرار گرفته است.پخش بار بهینه توابع هدف یک سیستم قدرت از جمله تابع هزینه سوخت ،آلودگی ،تلفات را بهینه می کند،و هم زمان قیود سیستم قدرت را نیز برآورده می کند.در کلی ترین حالتopf یک مساله بهینه سازی غیر خطی ،غیر محدب،مقیاس بزرگ،و ایستا می باشد که می تواند شامل متغیرهای کنترلی پیوسته و گ...