The study of computable structures and equivalence relations lies at the intersection of computability theory, algebra and logic, and provides essential insights into the classification and decision ...

Given an ergodic measured discrete equivalence relation 𝓡 and an ergodic subrelation 𝒮 ⊂ 𝓡 of finite index, C. Sutherland showed that they are represented by the cross products 𝓟 ⋊αG and 𝓟 ⋊αH of ...

In this paper we prove that a map induced from a shape fibration is a shape fibration. We define a fiber shape equivalence relation between shape fibrations. Also, generalizing the homotopy relation, ...