In Exercises 17-30, either prove that the wff is a valid argument or give an interpretation in which it is false. 17. (3x)[A(x) ^ B(x)] (3x)4(x) ^ (3x)B(x) 18. (3x)[R(x) V S(x)] (3x)R(x) V (3x)S(x) 19. (3x)P(x) (3x)(y)Q(x, y) (3x)(y) [P(x) ^ Q(x, y)] 20. (Vx) [P(x) Q(x)] [(Vx)P(x) (Vx)Q(x)] 21. (Vx)(P(x))' (Vx)(P(x) Q(x)) 22. [(Vx)P(x) (V\x)Q(x)] (Vx)[P(x) Q(x)] 23. (3x)(Vy)Q(x, y) (Vy)(3x)Q(x, y) 24. (Vx)P(x) V (3x)Q(x) (Vx)[P(x) VQ(x)] 25. (Vx)[A(x) B(x)] [(3x)A(x) (3x)B(x)] 26. (Vy)[Q(x, y) P(x)] [(y)Q(x,y) P(x)] 27. [P(x) (y)Q(x, y)] (=y)[P(x) Q(x, y)] 28. (Vx)(P(x) VQ(x))^(3x)Q(x) (3x)P(x) 29. (3x) [P(x) ^ Q(x)]^(Vy)[Q(y) R(y)] (3x)[P(x) ^ R(x)] 30. (Vx)(Vy)[(P(x) ^ S(x, y)) Q(y)] ^ (3x)B(x) ^ (Vx)(B(x) P(x)) ^ (Vx)(y)S(x, y) (3x)Q(x)