Editing Descriptive set theory (section)

{{short description|Subfield of mathematical logic}}
In [[mathematical logic]], '''descriptive set theory''' ('''DST''') is the study of certain classes of "[[well-behaved]]" [[set (mathematics)|subset]]s of the [[real line]] and other [[Polish space]]s. As well as being one of the primary areas of research in [[set theory]], it has applications to other areas of mathematics such as [[functional analysis]], [[ergodic theory]], the study of [[operator algebras]] and [[Group action (mathematics)|group actions]], and [[mathematical logic]].