MJ

"Writing subsets for a real-world situation"

Key Concepts of Sets and Subsets

  • Definition of a Set: A collection of distinct objects, considered as an object in its own right.

  • Roster Form: A way to list the elements of a set by explicitly listing each element.

  • Subset: A set that contains some or all elements of another set.

  • Proper Subset: A subset that is not identical to the original set (does not contain all elements of the original set).

Problem Example

Scenario

  • Novels on Shen's Reading Table: Sybil, Emma, Ulysses.

Task

  • Shen can choose to take some or none of the novels, but not all.

Objective

  • List all possible subsets of the novels Shen can take, excluding the full set.

Solution Steps

  1. Single Novels:

    • Shen can choose one novel:
      • {Sybil}
      • {Emma}
      • {Ulysses}
  2. Pairs of Novels:

    • Shen can choose two novels at a time:
      • {Sybil, Emma}
      • {Sybil, Ulysses}
      • {Emma, Ulysses}
  3. Empty Set:

    • Shen can also choose none of the novels, represented as:

Final List of Proper Subsets

  • The complete list of proper subsets that Shen can take:
      • {Sybil}
    • {Emma}
    • {Ulysses}
    • {Sybil, Emma}
    • {Sybil, Ulysses}
    • {Emma, Ulysses}

Conclusion

  • All Possible Subsets: The possible subsets of the set {Sybil, Emma, Ulysses} excluding the original set are:
    • {Sybil}, {Emma}, {Ulysses}, {Sybil, Emma}, {Sybil, Ulysses}, {Emma, Ulysses}, ∅.",