Field of Sets
  • is a mathematical structure consisting of a pair (𝑋,𝐹) where:
    • 𝑋 is a set
    • 𝐹 is a family of subsets of 𝑋 called an algebra over 𝑋 following the conditions:
      • 𝐹 contains the empty set as an element; βˆ…βˆŠπΉ
      • 𝐹 is closed under the complement of 𝑋; if {π‘₯}∊𝐹, then 𝑋\{π‘₯}∊𝐹
      • 𝐹 is closed under finite unions; if {π‘₯}∊𝐹 and {𝑦}∊𝐹, then {π‘₯}⋃{𝑦}∊𝐹
      • 𝐹 is closed under finite intersections; if {π‘₯}∊𝐹 and {𝑦}∊𝐹, then {π‘₯}β‹‚{𝑦}∊𝐹
  • field of sets play an essential role in the representation theory of Boolean algebra. Every Boolean algebra can be represented as a field of sets
  • if 𝐹 is also closed under countable unions and/or intersections, then 𝐹 is also aΒ Οƒ-algebra