Local stability in structures with a standard sort

Abstract

Recently, a classical approach to continuous structures has been proposed in [ABBMZ] and [Z] that extends the class of structures falling under the scope of [HI] or [BBHU]. These articles introduce the notion of structures with a standard sort. We discuss local stability in this context. We examine three variants of the order property which are prima facie non equivalent. For each variant we show that sets externally definable by stable formulas are definable in some appropriate sense.