\[DoubleDownArrow] (Mathematica Character Name)

Unicode: 21D3. Infix arrow operator. x ⇓ y is by default interpreted as DoubleDownArrow[x,y]. Extensible character.

\[DoubleLongLeftArrow] (Mathematica Character Name)

Unicode: 27F8. Alias: Esc <== Esc. Infix arrow operator. x ⟸ y is by default interpreted as DoubleLongLeftArrow[x,y].

\[DoubleLongLeftRightArrow] (Mathematica Character Name)

Unicode: 27FA. Alias: Esc <==> Esc. Infix arrow operator. x ⟺ y is by default interpreted as DoubleLongLeftRightArrow[x,y]. Not the same as \[Equivalent].

\[DoubleLongRightArrow] (Mathematica Character Name)

Unicode: 27F9. Alias: Esc ==> Esc. Infix arrow operator. x ⟹ y is by default interpreted as DoubleLongRightArrow[x,y].

\[DoubleUpArrow] (Mathematica Character Name)

Unicode: 21D1. Infix arrow operator. x ⇑ y is by default interpreted as DoubleUpArrow[x,y]. Extensible character.

\[DoubleUpDownArrow] (Mathematica Character Name)

Unicode: 21D5. Infix arrow operator. x ⇕ y is by default interpreted as DoubleUpDownArrow[x,y]. Extensible character.

\[DownArrowBar] (Mathematica Character Name)

Unicode: 2913. Infix arrow operator. x ⤓ y is by default interpreted as DownArrowBar[x,y]. Sometimes used as an indicator of depth. Extensible character.

\[DownArrowUpArrow] (Mathematica Character Name)

Unicode: 21F5. Infix arrow operator. x ⇵ y is by default interpreted as DownArrowUpArrow[x,y]. Extensible character.

\[DownBreve] (Mathematica Character Name)

Unicode: F755. Alias: Esc dbv Esc. Letter-like form. Used in an overscript position as a diacritical mark.

\[DownExclamation] (Mathematica Character Name)

Unicode: 00A1. Alias: Esc d! Esc. Letter-like form. Used in Spanish.