code: private boolean containsEliminated(final CLClause c) {
          for (int i = 0; i < c.lits().size(); i++) { if (var(c.lits().get(i)).state() == CLVar.State.ELIMINATED) { return true; } }
          return false;
      }
docs: Returns {@code true} if a given clause contains an eliminated variable, {@code false} otherwise.
  @param c the clause
  @return {@code true} if a given clause contains an eliminated variable