NotGreaterGreater 
NotGreaterGreater[x,y,…]
displays as .
Details

- NotGreaterGreater[x,y,…] has no built-in meaning.
is by default interpreted as NotGreaterGreater[x,y].
can be entered as \[NotGreaterGreater].
Examples
Basic Examples (1)
Wolfram Research (1996), NotGreaterGreater, Wolfram Language function, https://reference.wolfram.com/language/ref/NotGreaterGreater.html.
Text
Wolfram Research (1996), NotGreaterGreater, Wolfram Language function, https://reference.wolfram.com/language/ref/NotGreaterGreater.html.
CMS
Wolfram Language. 1996. "NotGreaterGreater." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/NotGreaterGreater.html.
APA
Wolfram Language. (1996). NotGreaterGreater. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/NotGreaterGreater.html