  Now, since Sx2, Sy2, Sz2 are compatible, there is an observable O such that Sx2, Sy2, Sz2 are all functions of O. So, the choice of an arbitrary such O fixes Sx2, Sy2, Sz2 and, since the latter can be directly associated with mutually orthogonal rays in H3, again fixes the choice of an orthogonal triple in H3. The resulting problem here is to assign numbers {1, 1, 0} to an orthogonal triple in H3 specified by the choice of O or, more directly, of Sx2, Sy2, Sz2. This is, of course, the mirror-image of our previous problem of assigning numbers {1, 0, 0} to such a triple, and we need not consider it separately.