@Override
    public boolean eval(Critter c) {
        // TODO implement me!
        // returns the boolean value of this condition for Critter c
		if (op.toString().equals("<"))
			return left.eval(c) < right.eval(c);
		else if (op.toString().equals("<="))
			return left.eval(c) <= right.eval(c);
		else if (op.toString().equals("="))
			return left.eval(c) == right.eval(c);
		else if (op.toString().equals(">"))
			return left.eval(c) > right.eval(c);
		else if (op.toString().equals(">="))
			return left.eval(c) >= right.eval(c);
		else if (op.toString().equals("!="))
			return left.eval(c) != right.eval(c);
		else
			System.out.println("Error in Comparison");
    	return true;
    }