  In A. Poltorak's concept, the reference frame in General Relativity is a
certain manifold equipped with a connection. The question under consideration
here is whether it is possible to join two events in the space-time by a
time-like geodesic if they are joined by a geodesic of the reference frame
connection that has a time-like initial vector. This question is interpreted as
whether an event belongs to the proper future of another event in the
space-time in case it is so in the reference frame. For reference frames of two
special types some geometric conditions are found under which the answer is
positive.
