Theorem 6.59. Let A be a set and let Ω be a collection of subsets of A (not necessarily a partiti...
Part(c) and partd(d)
1.34 Let A. A.. be a countable collection of subsets of U.Prove the following. a) If B cU, An, then B U,(An n B). b) If Un An-U, then E U(An E) for each subset E of U c) If Ai, A2,... are pairwise disjoint, so are Ain E, A2n E,... for each subset E of U d) We say that Ai, A2,... form a partition of U if they are pairwise disjoint and their union is...
(1) Let Ω be a set, and let Ao be a family of subsets of $2. Prove that there exists a minimal-algebra in Ω containing 4). In other wo)rds. prove that there exists a 8 σ-algebra A in 12 such that A C A, and . if A, is any σ-algebra in Ω with Ao c A,, then A c A,
(1) Let Ω be a set, and let Ao be a family of subsets of $2. Prove that there...
. Let C be a collection of open subsets of R. Thus, C is a set whose elements are open subsets of R. Note that C need not be finite, or even countable. (a) Prove that the union U S is also an open subset of R. SEC (b) Assuming C is finite, prove that the intersection n S is an open subset of R. SEC (c) Give an example where C is infinite and n S is not open....
7. Let A, , An be non-empty subsets of a finite set Ω. If 1 k n and Ek is the set of elements in Ω which belong to at least k of the Ai's show that Pal i-1
7. Let A, , An be non-empty subsets of a finite set Ω. If 1 k n and Ek is the set of elements in Ω which belong to at least k of the Ai's show that Pal i-1
3. (20 pts) Let ụ be a finite set, and let S = {Si, S , S,n} be a collection of subsets of U. Given an integer k, we want to know if there is a sub-collection of k sets S' C S whose union covers all the elements of U. That is, S k, and Us es SU. Prove that this problem is NP-complete. 992 m SES, si
3. (20 pts) Let ụ be a finite set, and let...
Let S be the set of all subsets of Z. Define a relation,∼, on S by “two subsets A and B of Z are equivalent,A∼B, if A⊆B.” Prove or disprove each of the following statements: (a)∼is reflexive(b)∼is symmetric(c)∼is transitive
4. Ranking/Unranking Subsets. Let A be a set of n elements and set Sk(A) be the collection of all k-element subsets of A. Recall that |Sk(A)I - (a.) (8 points) Describe a ranking algorithm to rank a k-element subset of an n-element set. (b.) (8 points) Describe an unranking algorithm to unrank an integer 0 < s< [into a ithm to unrank an integer 0 S s <C) k-element subset of an n-element set. (c.) (10 points) As examples, let...
b and c please explian thx
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post the question from the book
Let 2 be a non-empty set. Let Fo be the collection of all subsets such that either A or AC is finite. (a) Show that Fo is a field. Define for E e Fo the set function P by ¡f E is finite, 0, if E is finite 1, if Ec is finite. P(h-10, (b) If is countably infinite, show P is finitely additive but not-additive. (c)...
OTO (7) (a) Let T = (a1, ..., ak) be a k-cycle in Sn, and let o E Sn. Prove that is the k-cycle (o(a), o(az),..., 0(ak)) (b) Let o,t e Sn. Prove that if t is a product of r pairwise disjoint cycles of lengths k1,..., kr, respectively, where kit..., +kr = n, then oto-1 is also a product of r pairwise disjoint cycles of lengths k1,..., kr. (c) Let T1 and T2 be permutations in Sn. Prove that...
Let P(X) be the power set of a non-empty set X. For any two subsets A and B of X, define the relation A B on P(X) to mean that A union B = 0 (the empty set). Justify your answer to each of the following? Isreflexive? Explain. Issymmetric? Explain. Istransitive? Explain.