code: public static <G extends Relatable<?>> Context down(final CompleteLattice lattice) {
          List<Object> elements = Arrays.asList(lattice.toArray());
          return new Context(elements, elements, new LessOrEqual());
      }
docs: Calculate the isomorphic down lattice.
  @param <G> element type
  @param lattice of elements
  @return the down lattice of the given complete lattice
  @see <a href="https://en.wikipedia.org/wiki/Upper_set">upper set</a>