B. P(A) is the set of subsets of a, a has four subsets, {a} is a subset of a, and a is not an element of P(A), so it should be ∈.

Using implication equivalence, de Morgan's law, association law, absorption law,

....& lt= & gt┐(┐r∨(q→p))∨(┐p∨q∨r)& lt； = & gt┐(┐r∨(┐q∨p))∨(┐p∨q∨r)& lt； = & gt(r∧(q∧┐p))∨(┐p∨q∨r)& lt； = & gt((r∧q∧┐p)∨┐p)∨q∨r)& lt； = & gt┐P∨Q∨R, this is the main conjunctive normal form, and its false assignment is 100, so the main conjunctive normal form is M4.

Then, the principal disjunctive paradigm is m0∨m 1∨m2∨m3∨m5∨m6∨m7.

The false assignment of the formula is 100, and the true assignment is 000,001,01,01,1,1.