Table of Contents

## What is an example of a not well-defined set?

Examples of not well-defined sets The “top 5 worst movies” for me could not be for you. The elements or members of the set are not distinct nor exact. The set includes unclear definitions. This is why these sets are considered not well-defined sets.

## What are the three examples of well-defined sets?

Well-defined Set. Set: A set is a well-defined collection of objects or ideas. Example: C = {red, blue, yellow, green, purple} is well-defined since it is clear what is in the set.

## What are the non examples of sets?

collection of great people of the world.

## What is roster method?

The roster method is defined as a way to show the elements of a set by listing the elements inside of brackets. An example of the roster method is to write the set of numbers from 1 to 10 as {1,2,3,4,5,6,7,8,9 and 10}. An example of the roster method is to write the seasons as {summer, fall, winter and spring}.

## What is a well-defined function?

A function is well-defined if it gives the same result when the representation of the input is changed without changing the value of the input. For instance if f takes real numbers as input, and if f(0.5) does not equal f(1/2) then f is not well-defined (and thus: not a function).

## Can a set be infinite?

An infinite set is a set whose elements can not be counted. An infinite set is one that has no last element. An infinite set is a set that can be placed into a one-to-one correspondence with a proper subset of itself.

## What are the examples of set?

A set is a collection of elements or numbers or objects, represented within the curly brackets { }. For example: {1,2,3,4} is a set of numbers.

## What is the symbol of set?

Symbol | Meaning | Example |
---|---|---|

{ } | Set: a collection of elements | {1, 2, 3, 4} |

A ∪ B | Union: in A or B (or both) | C ∪ D = {1, 2, 3, 4, 5} |

A ∩ B | Intersection: in both A and B | C ∩ D = {3, 4} |

A ⊆ B | Subset: every element of A is in B. | {3, 4, 5} ⊆ D |

## What is well-defined set and not well-defined set?

Thus, the basic concepts of sets is a well-defined collection of objects which are called members of the set or elements of the set. Objects belongs to the set must be well-distinguished. Well-defined means, it must be absolutely clear that which object belongs to the set and which does not.

## Which is an example of a well defined set?

In mathematics, a well-defined set clearly indicates what is a member of the set and what is not. For example, a set that is identified as “the set of even whole numbers between 1 and 11” is a well-defined set because it is possible to identify the exact members of the set: 2, 4, 6, 8 and 10.

## What is the definition of a non-wellfounded set?

The term non-wellfounded set refers to sets which contain themselves as members, and more generally which are part of an infinite sequence of sets each term of which is an element of the preceding set. So they exhibit object circularity in a blatant way.

## Why are non-wellfounded sets ruled out of set theory?

So they exhibit object circularity in a blatant way. Discussion of such sets is very old in the history of set theory, but non-wellfounded sets are ruled out of Zermelo-Fraenkel set theory (the standard theory) due to the Foundation Axiom ( FA ). As it happens, there are alternatives to this axiom FA.

## Is the term most dangerous a well defined set?

(iv) The term most dangerous is not a well—defined term. An animal may be most dangerous for one person and may not be for the other. So, it is not well—defined. Hence, it is not a set.