If Superman is able and willing to prevent evil, he would do so. If Superman is unable to prevent evil, he would be ineffective. If he is unwilling to prevent evil, he would be malevolent. If Superman exists, he is neither ineffective nor malevolent. Superman does not prevent evil. Argue that Superman does not exist. Let p = " Superman is able to prevent evil." q = " Superman is willing to prevent evil." r = "Superman prevents evil." s = "Superman is ineffective." t = "Superman is malevolent." u = "Superman exists." Write each premise in terms of p, q, r, w, t, u and logical operators

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?

In which job role will you be creating e-papers, newsletters and preiodicals

Examine the list below. which factors positively affect lifetime income? check all that apply.