The proposition p + (q + 9) is A. neither a tautology nor a contradiction B. a tautology C. a tautology and a contradiction D. a contradiction Let A = {a,b,c,d) and let P be a partial order on A such...

The proposition p + (q + 9) is A. neither a tautology nor a contradiction B. a tautology C. a tautology and a contradiction D. a contradiction Let A = {a,b,c,d) and let P be a partial order on A such that bPd,dPa,cPd, and b and care incomparable. Which of the following statements is true? OA. P ={(b.0),(d,a),(c,d)). B. P = {(b,b),