5. On this problem set, you that every propositional logic formula could be written in terms of just the-, and T, You also saw that you could use just-, and L, or alternatively that you could ust use?:, T, and L. Interestingly, you cannot express every possible propositional logic formula using just the-and L connectives. Prove why not. 5. On this problem set, you that every propositional logic formula could be written in terms of just the-, and T, You also saw that you could use just-, and L, or alternatively that you could ust use?:, T, and L. Interestingly, you cannot express every possible propositional logic formula using just the-and L connectives. Prove why not