منابع مشابه
Definable Types in Presburger Arithmetic
We consider the first order theory of (Z,+, <), also known as Presburger arithmetic. We prove a characterization of definable types in terms of prime models over realizations, which has a similar flavor to the Marker-Steinhorn Theorem of o-minimality. We also prove that a type over a model is definable if and only if it has a unique coheir to any elementary extension, which is a characterizatio...
متن کاملDefinable norms and definable types over Banach spaces
A central question in Banach space theory has been to identify the class of Banach spaces that contain almost isometric copies of the classical sequence spaces `p and c0. Banach space theory entered a new era in the mid 1970’s, when B. Tsirelson [34] constructed the first space not containing isomorphic copies any of the classical sequence spaces. Tsirelson’s space has been called “the first tr...
متن کاملExtended Locally Definable Acceptance Types
Hertrampf’s locally definable acceptance types showed that many complexity classes can be defined in terms of polynomially time bounded NTM’s with simple local conditions on the nodes of its computation tree, rather than global concepts like number of accepting paths etc. We introduce extended locally definable acceptance types as a generalization of Hertrampf’s concept in order to formally cap...
متن کاملUnambiguous Computations and Locally Definable Acceptance Types
Hertrampf’s locally definable acceptance types show that many complexity classes can be defined in terms of polynomial time bounded NTM’s with simple local conditions on the nodes of its computation tree, rather than global concepts like number of accepting paths etc. We introduce a modification of Hertrampf’s locally definable acceptance types which allows to get a larger number of characteriz...
متن کاملDefinable choice for a class of weakly o-minimal theories
Given an o-minimal structure M with a group operation, we show that for a properly convex subset U , the theory of the expanded structure M′ = (M, U) has definable Skolem functions precisely when M′ is valuational. As a corollary, we get an elementary proof that the theory of any such M′ does not satisfy definable choice. §
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: Transactions of the American Mathematical Society
سال: 1986
ISSN: 0002-9947
DOI: 10.1090/s0002-9947-1986-0833696-8