Spectral Universality of Linear Orders with One Binary Relation

Abstract

© 2020, Pleiades Publishing, Ltd. We show the spectral universality of the class of structures that are linear orders with an additional binary relation and hence with an n-ary relation for each n ≥ 2. To this end, we study the category of the structures. We then obtain some other algorithmic properties of the category by using the notion of a computable functor which was studied in recent papers by other authors.