number 20

In Exercises 13-24, use propositional logic to prove that the argument is valid. Section 1.2 Propositional Logic D) 18. (A ( BC)]^(AV D') AB ( DC) 19. (A' B') ABA( A C ) 20. (A + B)^[B( C D)]^ [A (B+C)] ( A 21. [A ( BC)] [B( AC)] 22. (A AB) (A B')' 23. (A CA(C B') ABA 24.[A (BVC)] AC' ( AB) 11iter the roliditurful