Is there anything common in between small oh and theta ?
i.e. If we consider a function $f(n)$, then what is the intersection of all the set of functions for which $f(n$) is the upper bound and the set of functions which are asymptotically equivalent to $f(n)$ ?
This seems to be null, but I'm not sure if that is true. And if possible, can you also point out the results of possible combinations of $o,O,ω,Ω,θ$ in same way ?