1 / 20

Sets, Relations, Life, and Death

Mathematically speaking…. Sets, Relations, Life, and Death. by Pavel Gladyshev. Objects. Chair, You, Me, 1, 2, 3, UCD, pack of pringles Any two objects x and y can be compared for equality:. Set. Unoprdered c ollecton of distinct objects (members)

Download Presentation

Sets, Relations, Life, and Death

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Mathematically speaking… Sets, Relations, Life, and Death by Pavel Gladyshev

  2. Objects • Chair, You, Me, 1, 2, 3, UCD, pack of pringles • Any two objects x and y can be compared for equality:

  3. Set • Unoprderedcollecton of distinct objects (members) • May contain other sets as members • Set names are written in capital Roman letters: A, B, N, R, …

  4. Membership

  5. Standard sets

  6. Set definition • Enumeration of elements of the set • Restriction of (i.e. selection of elements from) an existing set • Combining existing sets using set operators

  7. Set Definition by Enumeration

  8. Set Definition by Restriction • A consists of all members of B for which the logical formula is true

  9. Logical formula • Basic statements • Connected with logical connectives

  10. If no base set is specified, x is assumed to be a member of the Universal set:

  11. Subset “A is a subset of B” if every element of A is a member of B. A ` ` B

  12. Set equality

  13. Set operators • Union • Intersection • Subtraction

  14. Set operations • Union: • Intersection: • Difference (“subtraction”)

  15. Assuming that • All men are mortal • Socratis is a man • Convince me that Socratis is mortal

  16. Tuple • Ordered sequence of objects • Same object can appear in a tuple several times • Elements of a tuple are referred to with subscripts:

  17. Relation A collection of links between elements of two or more sets: Set B (Range of the retation) a 1 b 2 c 3 Set A (Domain of the retation)

  18. Relation • Formally defined as a set of tuples: • Can be viewed as predicate:

  19. Let’s talk mathematically about sexuality • Define concepts “heterosexual”, “gay”, “lesbian”, etc. • Convince me using Venn diagrams that gays are human beings.

More Related