On applications of the Taylor formula in some quasispaces

We consider some metric spaces with quasimetric (quasispaces) comprising uniformly regular (equiregular) Carnot–Carathéodory quasispaces whose quasimetric is induced by $C^{\varUpsilon-1}$-smooth vector fields of formal degree not higher than $\varUpsilon$. For these spaces, some analogues of the Campbell–Hausdorff formula are derived, which allows us to prove a theorem on a nilpotent tangent cone, a theorem on isomorphism of various nilpotent tangent cones defined at a common point, and a local approximation theorem.