(A) IF P AND Q ARE BOTH FALSE, (P IMP2 Q) ∧ (Q IMP2 P) IS FALSE, BUT P ↔ Q IS TRUE

75. (a) If p and q are both false, (p imp2 q) ∧ (q imp2 p) is false, but p ↔ q is true.

(b) Making the suggested change does not alter the last line of the imp2 table.