On coincidence of dimensions in closed ordered differential fields

Pantelis E. Eleftheriou, Omar Leon Sanchez, Nathalie Regnault

Published 2020-02-28Version 1

Let $(R, \delta)$ be a closed ordered differential field, and $C$ its field of constants. In this note, we prove that for sets definable in the pair $(R, C)$, the $\delta$-dimension and the large dimension coincide. As an application, we characterize the definable sets that are internal to $C$, as those sets that are definable in $(R, C)$ and have $\delta$-dimension $0$. We further show that having $\delta$-dimension $0$ does not generally imply co-analyzability in $C$.