• Alias: un.
• Infix operator with built-in evaluation rules.
• x y is by default interpreted as Union[x, y].
• The character is sometimes called "cup"; but see also \[Cup] .
• See Section 1.10.4, Section 3.10.1 and Section 3.10.4.
• See also: \[Intersection] , \[SquareUnion] , \[UnionPlus] , \[Cup] , \[Vee] .