\[UpperLeftArrow] (Mathematica Character Name)

Unicode: 2196. Infix arrow operator. x ↖ y is by default interpreted as UpperLeftArrow[x,y]. Extensible character; grows by default to limited size.

\[UpperRightArrow] (Mathematica Character Name)

Unicode: 2197. Infix arrow operator. x ↗ y is by default interpreted as UpperRightArrow[x,y]. Extensible character; grows by default to limited size.

\[Upsilon] (Mathematica Character Name)

Unicode: 03C5. Aliases: Esc u Esc, Esc upsilon Esc. Greek letter.

\[UpTeeArrow] (Mathematica Character Name)

Unicode: 21A5. Infix arrow operator. x ↥ y is by default interpreted as UpTeeArrow[x,y]. Extensible character.

\[UpTee] (Mathematica Character Name)

Unicode: 22A5. Alias: Esc uT Esc. Infix relational operator. x ⊥ y is by default interpreted as UpTee[x,y]. Used in geometry to indicate perpendicular. Used in number theory ...

\[WarningSign] (Mathematica Character Name)

Unicode: F725. Letter-like form. Used in yellow to indicate messages and other warnings in the default style for Mathematica notebooks. Based on an international standard ...

\[WatchIcon] (Mathematica Character Name)

Unicode: 231A. Letter-like form. Used to indicate a calculation that may take a long time.

\[Xi] (Mathematica Character Name)

Unicode: 03BE. Aliases: Esc x Esc, Esc xi Esc. Greek letter.

\[Xor] (Mathematica Character Name)

Unicode: 22BB. Alias: Esc xor Esc. Infix operator with built-in evaluation rules. x ⊻ y is by default interpreted as Xor[x,y].

DirichletDistribution (Built-in Mathematica Symbol)

DirichletDistribution[{\[Alpha]_1, ..., \[Alpha] k +1}] represents a Dirichlet distribution of dimension k with shape parameters \[Alpha]_i.