A conceptually compelling class. 

-A rond de jambe combination exhibiting a great degree of circularity in both form and pattern of movement; laden with luxurious cambrEs, it circles to a natural close with the other half of the port de corps en rond.
-Rond de jambe fouettE combination at Center becomes math-y: Does this center combination lie in the set of reversibles, R? If so, what is its reverse? As in math, certain paths are fundamentally restricted; certain operations are performed in order to produce a particular outcome; the existence of constants. Leads to a curious idea: the symbolic representation of ballet combinations.
-There is no right or wrong; just closed systems that obey fundamental rules and build on them. We can only define or prove something as a truth within the closed system to which it belongs. Moreover, as Kurt Godel proved in 1931, all logical systems of any complexity are incomplete. Computers will never be as smart as human beings, and human beings can never know themselves fully. That said, some closed systems are more general, ie: more universal, than others. For instance, ballet is a fairly general human-centric system. A central tenet of contemporary ballet is that movement emanates from the beginning of the rib cage, the focal point of the modern classical sense of curvature.