  We consider textures of biaxial nematics confined between two parallel
plates. The boundary conformations at the bordering plates are supposed to be
identical, the gradients of the order parameter being generally nonzero. We
claim that for any texture (including stable uniform order parameter alignment)
there exists its counterpart texture which is also a minimum of the gradient
elastic energy. Our arguments are based on the topological analysis of the
conformation of the order parameter.
