public void addVariable(Variable v, boolean vSign) {
		//make a new literal
		Literal newLit = new Literal(v, vSign);

		if(SsatSolver.DEBUG) {
			System.out.println("Adding a literal: '" + newLit + "'");
		}

		//add it to the vectors
		literals.add(newLit);

		//make sure v has the number of times it appears positive or negative correct
		if(vSign) {
			v.incTimesPositive();
		} else {
			v.incTimesNegative();
		}
	}