Language equations with complementation: Decision problems

Strict Language Inequalities and Their Decision Problems

Systems of language equations of the form {φ(X1, . . . , Xn) = ∅, ψ(X1, . . . , Xn) 6= ∅} are studied, where φ,ψ may contain set-theoretic operations and concatenation; they can be equivalently represented as strict inequalities ξ(X1, . . . , Xn) ⊂ L0. It is proved that the problem whether such an inequality has a solution is Σ2-complete, the problem whether it has a unique solution is in (Σ3∩Π...

global results on some nonlinear partial differential equations for direct and inverse problems

در این رساله به بررسی رفتار جواب های رده ای از معادلات دیفرانسیل با مشتقات جزیی در دامنه های کراندار می پردازیم . این معادلات به فرم نیم-خطی و غیر خطی برای مسایل مستقیم و معکوس مورد مطالعه قرار می گیرند . به ویژه، تاثیر شرایط مختلف فیزیکی را در مساله، نظیر وجود موانع و منابع، پراکندگی و چسبندگی در معادلات موج و گرما بررسی می کنیم و به دنبال شرایطی می گردیم که متضمن وجود سراسری یا عدم وجود سراسر...

The Complexity of Some Complementation Problems

Foundations for Decision Problems in String Logic with Equations, Regular Membership and Length Constraints (Technical Report)

In this paper, we consider the satisfiability problem for string logic with equations, regular membership and Presburger constraints over length functions. The difficulty comes from multiple occurrences of string variables making state-of-the-art algorithms non-terminating. Our main contribution is to show that the satisfiability problem in a fragment where no string variable occurs more than t...

Language equations