In TeXForm#
TeXForm parses this entry as a character leaf mapped to U+21DA (LEFTWARDS TRIPLE ARROW).
\to\rightarrow\longrightarrow\mapsto\xrightarrow\Rightarrow\Leftrightarrow\leftarrow\longmapsto\hookrightarrow\Longrightarrow\Lleftarrow
\LleftarrowSymbol
The ⇚ symbol (Leftwards triple arrow, U+21DA), written as \Lleftarrow in LaTeX math mode.