code: public BooleanFormula andWith(BooleanFormula other) {
  		if (other.isTrue()) {
  			return this;
  		}
  		if (other.isFalse() || isFalse()) {
  			if (booleanTerms == null) {
  				booleanTerms = new HashSet<BooleanTerm>();
  			} else {
  				booleanTerms.clear();
  			}
  			isSimplified = true;
  			return this;
  		}
  		if (isTrue()) {
  			booleanTerms = new HashSet<BooleanTerm>(other.booleanTerms);
  			return this;
  		}
  		BooleanFormula newTerms = new BooleanFormula();
  		for (BooleanTerm otherTerm : other) {
  			for (BooleanTerm term : booleanTerms) {
  				BooleanTerm newTerm = term.andWith(otherTerm);
  				if (newTerm != null) {
  					newTerms.add(newTerm);
  				}
  			}
  		}
  		booleanTerms = newTerms.booleanTerms;
  		isSimplified = newTerms.isSimplified;
  		return this;
  	}
docs: Logically ands the provided terms with the terms in the formula,
  replacing this formula with the result
  
  @param other
  the terms to and with this formula
  @return this object.