Using Baire Category Theorem to show
A Gδ set is the countable intersection of open sets. An Fσ sets is the countable union of closed sets.
Using Baire Category Theorem to show A Gδ set is the countable intersection of open sets....
topology class
want proof for theorem 7.14 using definition 7.13
please explain well.
Definition 7.13. X is a Baire space if the intersection of each countable family of dense open sets is dense. A set A c X is nowhere dense in X if (T)0-0, A set A C X is first category in X if A-Un=1 An, where each An is nowhere dense in X. If a set is not first category, it is called second category. (Topologically, seoond...
topology class
want proof for theorem 7.16 using definition 7.15
Definition 7.13. X is a Baire space if the intersection of each countable family of dense open sets is dense. A set A C X is nowhere dense in X if (A)A set ACXis first category in X if AAn, whcre cach An is nowbere dense in X. If a set is not first category, it is called second category. (Topologically, second category sets in X are thick" and first...
3. Let E E Lm* (Lebesgue measurable set). Prove that there exist a set G (a countable intersection of open sets), and a set F (a countable union of closed sets) such that F CE C G and m* (F) the Lebesgue measure of a set Hint: The Lebesgue measure can be calculated in terms of open and closed sets m* (E) m* (G), where m* denotes
3. Let E E Lm* (Lebesgue measurable set). Prove that there exist a...
1. Show that if A and B are countable sets, then AUB is countable. 2. Show that if An are finite sets indexed by positive integers, then Un An is countable. 3. Show that if A and B are countable sets, then A x B is countable. 4. Show that any open set in R is a countable union of open intervals. 5. Show that any function on R can have at most countable many local maximals. Us
want proof for theorem 7.12 using definition 7.9
Problem 7.7. Give an example of a space that is connected, but not path con- nected. Problem 7.8. Show that R" is not homeomorphic to R if n>1 Definition 7.9. Let be a point in X. Then X is called locally path connected at a if for each open set U containing r, there is a path connected open set V containing r such that V CU. If X is locally path...
5- Recall that a set KCR is said to be compact if every open cover for K has a finite subcover 5-1) Use the above definition to prove that if A and B are two compact subsets of R then AUB is compact induction to show that a finite union of compact subsets of R is compact. 5-2) Now use 5-3) Let A be a nonempty finite subset of R. Prove that A is compact 5-4) Give an example of...
. 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....
Please prove
Theorem 7.20: Let (X, T) be a topological space. Then the following are all topological properties the number of elements in X, the number of T-open sets, and having a T-open set containing n elements (for any natural number n
Theorem 7.20: Let (X, T) be a topological space. Then the following are all topological properties the number of elements in X, the number of T-open sets, and having a T-open set containing n elements (for any natural...
O FUNCTIONS AND GRAPHS Union and intersection of intervals B and C are sets of real numbers defined as follows. B={v | v<3) C={v | v>6) Write B U C and B n C using interval notation. If the set is empty, write Ø. BUC- (0,0) [0,0] (0,0) (0,0) DUD BNC = 00 -00 x 5 ? 4 Explanation Check Eng RO tv
3. (a) Prove the following: Cantor's Intersection Theorem: Let (X, d) be a complete metric space and {Anymore a nested sequence of non-empty closed sets whose diameters D(An) have limit 0. Then An has exactly one member. csc'anno proach onsdelered. c) Show that, in part (a), n A, may be empty if the requirement that the diameters