Abstract
1. In an Abelian group, a module, or more generally a one-based group H, the only definable groups are the obvious ones: if G is interpretable in H, then it has a definable subgroup of finite index which is definably isomorphic to a quotient A/B, where A and B are definable subgroups of a Cartesian power of H. 2. In such a group the introduction of those quotient groups weakly eliminates imaginary elements. More generally, for a stable theory the existence of canonical real bases for complete types implies the elimination of imaginary elements. 3. A group which is interpretable in a one-based structure is one-based. The property of being one-based is preserved by interpretation for theories of finite rank but not in general.
Similar content being viewed by others
Literature cited
Wanda Szmielew, "Elementary properties of Abelian groups," Fundamenta Math.,41, 64–70 (1955).
Walter Baur, "Elimination of quantifiers for modules," Israel J. Math.,25, 64–70 (1976).
Ehud Hrushovski and Anand Pillay, "Weakly normal groups," in: Logic Colloquium '85, North Holland (1987), pp. 233–244.
B. Poizat, "A propos de groupes stables," in: Logic Colloquium '85, North Holland (1987), pp. 245–265.
Mike Prest, Model Theory and Modules, Cambridge University Press (1987).
B. Poizat, Groupes Stables, Nur al-Mantiq wal-ma'rifah, Villeurbanne (1987).
Bruno Poizat, "Une theorie de Galois imaginaire," J. Symb. Logic,48, 1151–1170 (1983).
Steve Buechler, ""Geometrical" stability theory," in: Logic Colloquium '85, North Holland (1987), pp. 53–66.
Author information
Authors and Affiliations
Additional information
Translated from French.
Translated from Algebra i Logika, No. 3, pp. 368–378, May–June, 1990.
Rights and permissions
About this article
Cite this article
Evans, D., Pillay, A. & Poizat, B. A group in a group. Algebra and Logic 29, 244–252 (1990). https://doi.org/10.1007/BF01979940
Issue Date:
DOI: https://doi.org/10.1007/BF01979940