  Refraction of obliquely incident plane waves due to the interface of a
vacuous half-space and a half-space occupied by a simply moving,
nondissipative, isotropic dielectric-magnetic medium is considered, when the
medium's velocity lies parallel to the interface and in the plane of incidence.
Counterposition of the refracted wavevector and time-averaged Poynting vector
occurs when the medium's velocity is sufficiently large in magnitude and makes
an obtuse angle with the incident wavevector. The counterposition induced by
relative motion occurs whether the refraction is negative or positive when the
medium is at rest.
