In TeXForm#
TeXForm parses this entry as a character leaf mapped to U+21C8 (UPWARDS PAIRED ARROWS).
\to\rightarrow\longrightarrow\mapsto\xrightarrow\Rightarrow\Leftrightarrow\leftarrow\longmapsto\hookrightarrow\Longrightarrow\upuparrows
\upuparrowsSymbol
The ⇈ symbol (Upwards paired arrows, U+21C8), written as \upuparrows in LaTeX math mode.