Oscillation, rotatability, and wandering characteristic indicators for differential systems determining rotations of plane

The oscillation, rotatability, and wandering characteristic indicators of Lyapunov type are studied for two-dimensional linear homogeneous differential systems that determine rotations of the phase plane. A complete set of order relations between them is obtained. For each of those indicators it is established whether it is continuous or discontinuous as a function of the coefficient of the system.