.
The notion of asymptotic growth can be used to partition the space of functions.
Two functions f(n) and g(n) are ``equal'' if neither is
asymptotically bigger than the other. We write this as .
Formally, if and only if there exists
scaling factors 
and 
and threshold 
such that 
for all 
.
It's a an f(n) sandwich on g(n) bread!
