What does the symbol <<< mean?

Question

Can anyone give the LaTeX code for the unusual symbol <<<, and perhaps provide some good examples of its use?

Does it mean "much much less than"?

Answer 1

From a cursory search, it appears that the triple less-than sign $\lll$ is not often used in a mathematical context but in a programming one (maybe an experienced programmer or two can weigh in). From the wiki page:

• In PHP, operator <<<OUTPUT is used to denote the beginning of a heredoc statement (where OUTPUT is an arbitrary named variable).
• In Bash, <<<word is used as a "here string," where word is expanded and supplied to the command on its standard input, similar to a heredoc.

At least in mathematics, it is clear that something like $a\ll b$ means "$a$ is much less than $b$." Other than that, however, it does not appear that the symbol $\lll$ is used in mathematical contexts (none that I have seen anyway). A look at the wiki page on inequalities yields similarly fruitless results for trying to find that symbol/notation in math.