A closure property of regressive isols
نویسندگان
چکیده
منابع مشابه
A Closure Property of Sets of Vectors
Our aim here is to study this property. The exclusion of the vector 0 is not essential in what follows. It turns out that many of the other properties of root systems of Lie algebras depend only on property P and are thus shared by a much wider class of vector systems. In the statements to follow it is assumed that all vectors considered come from a real Euclidean space F of finite dimension »....
متن کاملGap-Definability as a Closure Property
Gap-definability and the gap closure operator were defined by S. Fenner, L. Fortnow and S. Kurth (J. Comput. System Sci. 48, 116 148 (1994)). Few complexity classes were known at that time to be gapdefinable. In this paper, we give simple characterizations of both gapdefinability and the gap-closure operator, and we show that many complexity classes are gap-definable, including P, P, PSPACE, EX...
متن کاملGap-deenability as a Closure Property ?
Gap-deenability and the gap-closure operator were deened in FFK91]. Few complexity classes were known at that time to be gap-deenable. In this paper, we give simple characterizations of both gap-deenability and the gap-closure operator, and we show that many complexity classes are gap-deenable, including P #P , P #P1] , PSPACE, EXP, NEXP, MP, and BP P. If a class is closed under union, intersec...
متن کاملRecursive Fibers of Rst Isols
Motivated by a conjecture of Ellentuck concerning fibers f^x(C), f recursive and C an element of one of Barback's "tame models" (Tame models in the isols, Houston J. Math. 12 (1986), 163-175), we study such fibers in the more general context of Nerode semirings. The principal results are that (1) all existentially complete Nerode semirings meet all of their recursive fibers, and (2) not all Ner...
متن کاملClosure for the property of having a hamiltonian prism
W c © ??? John Wiley & Sons, Inc. e prove that a graph G of order n has a hamiltonian prism if and only if the graph Cl4n/3−4/3(G) has a hamiltonian prism where Cl4n/3−4/3(G) is the graph obtained from G by sequential adding edges between non-adjacent vertices whose degree sum is at least 4n/3− 4/3. We show that this cannot be improved to less than 4n/3− 5.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Rocky Mountain Journal of Mathematics
سال: 1972
ISSN: 0035-7596
DOI: 10.1216/rmj-1972-2-1-1