What does $\ll$ mean? I saw two less than signs on this Wikipedia article and I was wonder what they meant mathematically.
http://en.wikipedia.org/wiki/German_tank_problem
EDIT: It looks like this can use TeX commands. So I think this is the symbol: $\ll$

In the occurrence of "$\ll$" you are asking about, it means "much less than". If you look at the fourth entry here, this is the first meaning listed for $\ll$.
As Charles has correctly pointed out, this symbol is also used in advanced mathematics to describe a certain relationship in the growth of two functions. That is the second meaning listed.
