Recursive properties of isomorphism types

Journal of the Australian Mathematical Society

Michael Moses¹ 

关键词: 03 D 45;   

DOI  :  10.1017/S1446788700023302

学科分类：数学（综合）

来源: Cambridge University Press

【 摘 要 】

For Γ a revursively enumerable set of formulae, a structure U on a recursive universe is said to be “Γ-recursively enumerable” if the satisfaction predicate restricted to Γ is recursively enumerable (equivalently, if the formulae of Γ uniformulae of Γ uniformly denote recursively enumerable relations on U).For recursively enumerable sets Γ1 ⊆ Γ2 of formulae we shall, under certain conditions, characterize structures U with the following properties.1) Every isomorphism form U to a Γ1-recursively enumerable structure is a recursive isomorphism.2) Every Γ1-recursively enumerable structure isomorphic to U is recursively isomorphic to U.3) Every Γ1-recursively enumerable structure isomorphic to U is Γ2-recursively enumerable.

【 授权许可】

Unknown