Non-commutative groupoids obtained from the failure of $3$-uniqueness in stable theories

Abstract

We construct a possibly non-commutative groupoid from the failure of $3$-uniqueness of a strong type. The commutative groupoid constructed by John Goodrick and Alexei Kolesnikov in \cite{GK} lives in the center of the groupoid. A certain automorphism group approximated by the vertex groups of the non-commutative groupoids is suggested as a "fundamental group" of the strong type.

16 pages, no figures. arXiv admin note: substantial text overlap with arXiv:1105.2921