A kind of categoricity

Computable Categoricity versus Relative Computable Categoricity

We study the notion of computable categoricity of computable structures, comparing it especially to the notion of relative computable categoricity and its relativizations. We show that every 1-decidable computably categorical structure is relatively ∆2-categorical. We study the complexity of various index sets associated with computable categoricity and relative computable categoricity. We also...

Categoricity of computable infinitary theories

Sukuk, a kind of hybrid Securities

Islamic securities (‘sukuk’) are securities which have the features of stocks and bonds toghater. Similar to stocks, these securities indicate a type of partnership. However, these securities usually bear a maturity date like bonds and contrary to stocks. This has resulted in sukuk (Islamic securities) to be considered as a type of hybrid securities. Hybrid security is a term used to describe a...

A KIND OF F-INVERSE SPLIT MODULES

Let M be a right module over a ring R. In this manuscript, we shall study on a special case of F-inverse split modules where F is a fully invariant submodule of M introduced in [12]. We say M is Z 2(M)-inverse split provided f^(-1)(Z2(M)) is a direct summand of M for each endomorphism f of M. We prove that M is Z2(M)-inverse split if and only if M is a direct...

Categoricity and Scott Families

Effective model theory is an area of logic that analyzes the effective content of the typical notions and results of model theory and universal algebra. Typical notions in model theory and universal algebra are languages and structures, theories and models, models and their submodels, automorphisms and isomorphisms, embeddings and elementary embeddings. In this paper languages, structures, and ...