Editing Data type (section)

===Intersection types===
{{Main|Intersection type}}
An intersection type is a type containing those values that are members of two specified types. For example, in [[Java (programming language)|Java]] the class {{code|Boolean}} implements both the {{code|Serializable}} and the {{code|Comparable}} interfaces. Therefore, an object of type {{code|Boolean}} is a member of the type {{code|Serializable & Comparable}}. Considering types as sets of values, the intersection type <math>\sigma \cap \tau</math> is the set-theoretic [[Intersection (set theory)|intersection]] of <math>\sigma</math> and <math>\tau</math>. It is also possible to define a dependent intersection type, denoted <math>(x : \sigma) \cap \tau</math>, where the type <math>\tau</math> may depend on the term variable <math>x</math>.<ref name=K03>{{cite conference |title=Dependent intersection: A new way of defining records in type theory |last1=Kopylov |first1=Alexei |year=2003 |publisher=IEEE Computer Society |book-title=18th IEEE Symposium on Logic in Computer Science |pages=86–95 |conference=LICS 2003 |doi=10.1109/LICS.2003.1210048 |citeseerx=10.1.1.89.4223 }}</ref>