api: YAML JSON TOON Database version: 1.0.0 format: toon dataset: id: 2891 slug: set-theory-basics title: Set Theory Basics description: Fundamental set operations and relations. summary: "The core vocabulary and notation of set theory: union, intersection, complement, subsets, power sets and Cartesian products, with set difference, symmetric difference, cardinality, membership, disjoint sets and De Morgan's laws." use_when[2]: You need the notation and meaning of a set operation.,You are translating between set language and logic or SQL. caveats[2]: Complement is relative to a stated universal set; without one it is undefined.,"Notations differ between textbooks (A^c, A', and a bar over A all denote complement)." related[3]: combinatorics-fundamentals,statistics-basics,sql-join-types entry_count: 14 fields[3]{section,field,type,example}: data,concept,string,Union data,notation,string,A ∪ B data,description,string,Elements in A or B or both. category: Mathematics category_slug: mathematics tags: "math,set-theory,logic" view_count: 71 created_at: 1793403093 updated_at: 1793403093 data[14]{concept,notation,description}: Union,A ∪ B,Elements in A or B or both. Intersection,A ∩ B,Elements common to A and B. Complement,A',Elements not in A within the universal set. Subset,A ⊆ B,Every element of A is also in B. Superset,A ⊇ B,A contains all elements of B. Power Set,P(A),Set of all subsets of A. Cartesian Product,A × B,Set of all ordered pairs from A and B. Set Difference,A ∖ B,Elements in A that are not in B. Symmetric Difference,A Δ B,Elements in exactly one of A or B. Empty Set,∅,The set with no elements; it is a subset of every set. Cardinality,|A|,The number of elements in A. Element Of,x ∈ A,x is a member of A. Disjoint Sets,A ∩ B = ∅,Sets with no elements in common. De Morgan's Laws,(A ∪ B)ᶜ = Aᶜ ∩ Bᶜ,"The complement of a union is the intersection of the complements, and the complement of an intersection is the union of the complements."