∀ {M : Type u_1} [inst : ConditionallyCompleteLattice M] [inst_1 : Group M] [MulLeftMono M] [MulRightMono M]
  {s t : Set M}, s.Nonempty → BddAbove s → t.Nonempty → BddAbove t → sSup (s * t) = sSup s * sSup t