Abstract
Let T be simple, work in 𝒞eq over a boundedly closed set. Let p∈ S(∅) be internal in a quasi-stably-embedded type-definable set Q (e.g., Q is definable or stably-embedded) and suppose (p,Q) is ACL-embedded in Q (see definitions below). Then Aut(p/Q) with its action on p𝒞 is type-definable in 𝒞eq over ∅. In particular, if p∈ S(∅) is internal in a stably-embedded type-definable set Q, and p𝒞∪ Q is stably-embedded, then Aut(p/Q) is type-definable with its action on p𝒞.
Citation
Bradd Hart. Ziv Shami. "On the type-definability of the binding group in simple theories." J. Symbolic Logic 70 (2) 379 - 388, June 2005. https://doi.org/10.2178/jsl/1120224718
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