Theorem 3.16. Suppose X is a set and S is a collection of subsets of X. Then S is a subbasis for some topology on X if and only if every point of X is in some element of S.

Elements Of Modern Algebra
8th Edition
ISBN:9781285463230
Author:Gilbert, Linda, Jimmie
Publisher:Gilbert, Linda, Jimmie
Chapter3: Groups
Section3.1: Definition Of A Group
Problem 42E: 42. For an arbitrary set , the power set was defined in Section by , and addition in was...
icon
Related questions
Question
100%

Could you explain how to show 3.16 in detail? Thank you! In particular, I am having hard time proving (<-) part.

Theorem 3.16. Suppose X is a set and S is a collection of subsets of X. Then S is a
subbasis for some topology on X if and only if every point of X is in some element of S.
Definition. Let (X,J) be a topological space and let S be a collection of subsets of X.
Then S is a subbasis for T if and only if the collection B of all finite intersections of
sets in S is a basis for T. An element of S is called a subbasis element or a subbasic
open set.
Theorem 3.15. Let (X,J) be a topological space, and let S be a collection of subsets of
X. Then S is a subbasis for T if and only if
(1) SCT, and
(2) for each set U in T and point p in U there is a finite collection {V}{=1 of elements of S
such that
n
PENVCU.
i=1
Transcribed Image Text:Theorem 3.16. Suppose X is a set and S is a collection of subsets of X. Then S is a subbasis for some topology on X if and only if every point of X is in some element of S. Definition. Let (X,J) be a topological space and let S be a collection of subsets of X. Then S is a subbasis for T if and only if the collection B of all finite intersections of sets in S is a basis for T. An element of S is called a subbasis element or a subbasic open set. Theorem 3.15. Let (X,J) be a topological space, and let S be a collection of subsets of X. Then S is a subbasis for T if and only if (1) SCT, and (2) for each set U in T and point p in U there is a finite collection {V}{=1 of elements of S such that n PENVCU. i=1
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps

Blurred answer
Knowledge Booster
Numerical Integration
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, advanced-math and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
Elements Of Modern Algebra
Elements Of Modern Algebra
Algebra
ISBN:
9781285463230
Author:
Gilbert, Linda, Jimmie
Publisher:
Cengage Learning,
Linear Algebra: A Modern Introduction
Linear Algebra: A Modern Introduction
Algebra
ISBN:
9781285463247
Author:
David Poole
Publisher:
Cengage Learning