Add unicode syntax for banana brackets
While there is a “pretty” unicode alternative available for “-<“ within arrow notation (⤙), banana brackets can only be written as “(|” and “|)”, which is a bit of an eyesore when they are used in the middle of the fancy arrow glyphs.
Maybe it would be convenient to add the following unicode alternatives, which to the best of my knowledge are mapped by default within the XCompose definitions shipped with XOrg.
⦆ right white parenthesis (U+2986) ⦅ left white parenthesis (U+2985)
Alternatively, these would also correspond well with the plain ASCII syntax:
⦇ z notation left image bracket (U+2987) ⦈ z notation right image bracket (U+2988)