code: protected void claBumpActivity(final MSClause c) {
      c.incrementActivity(claInc);
      if (c.activity() > 1e20) {
        for (final MSClause clause : learnts)
          clause.rescaleActivity();
        claInc *= 1e-20;
      }
    }
docs: Bumps the activity of the given clause.
  @param c the clause