Description: Define the supremum of a set of Hilbert lattice elements. See chsupval2 for its value. We actually define the supremum for an arbitrary
collection of Hilbert space subsets, not just elements of the Hilbert
lattice CH , to allow more general theorems. Even for general subsets
the supremum still a Hilbert lattice element; see hsupcl . (Contributed by NM, 9-Dec-2003)(New usage is discouraged.)