Show that ‘the closure operators cannot be omitted’ from the formulas above
in general. That is, one might have, for suitable pairs of closed convex cones in
duality (C,C)˜ and (D, D)˜ in Rn,
C + D = (C˜ ∩ D)˜ ◦
and
(CM˜ )
◦ = MC.