... connectivesand parentheses in particular ways. For example, A 1123, (A 2→ ( A 0)),and ((( A 1) → (A 1→ A 7)) → A 7) are all formulas, but X3, (A 5),() A 41, A 5→ A 7,and (A 2→ ( A 0) are ... with propositional logic,developed here as a warm-up for the development of first-order logicproper in Part II.Propositional logic attempts to make precise the relationships thatcertain connectives ... sentenceswhich appear in it. Using the interpretations just given of A 0and A 1,the formula (A 0→ ( A 1)) is true, but if we instead use A 0and A 1to interpret “My telephone is ringing” and “Someone...