code: protected boolean trivialClause() {
          boolean res = false;
          final LNGIntVector newAddedLits = new LNGIntVector(this.addedlits.size());
          for (int i = 0; i < this.addedlits.size(); i++) {
              final int lit = this.addedlits.get(i);
              assert lit != 0;
              final int m = marked(lit);
              if (m < 0) {
                  res = true;
                  break;
              } else if (m == 0) {
                  newAddedLits.push(lit);
                  mark(lit);
              }
          }
          this.addedlits = newAddedLits;
          unmark();
          return res;
      }
docs: Returns {@code true} if the current clause is a trivial clause, {@code false} otherwise.
  @return {@code true} if the current clause is a trivial clause