Abstract
We obtain several results concerning the concept of isotypic structures.
Namely we prove that any field of finite transcendence degree over a prime
subfield is defined by types; then we construct isotypic but not isomorphic
structures with countable underlying sets: totally ordered sets, fields, and
groups. This answers an old question by B. Plotkin for groups.
Publisher
Centre pour la Communication Scientifique Directe (CCSD)