In TeXForm#
TeXForm parses this entry as a character leaf mapped to U+22F0 (UP RIGHT DIAGONAL ELLIPSIS).
The ⋰ symbol (Up right diagonal ellipsis, U+22F0), written as \iddots in LaTeX math mode.
TeXForm parses this entry as a character leaf mapped to U+22F0 (UP RIGHT DIAGONAL ELLIPSIS).