Comment #19 on issue 2085 by nicolas.pourcelot: Limit code severely broken.
http://code.google.com/p/sympy/issues/detail?id=2085

gruntz() relies on asymptotic expansions, that's why it can't handle things like limit(cos(x)/x,x,oo), since cos(x) have no asymptotic expansion on oo.

Since sin(x) and cos(x) are bounded (if x is real), we could use a rule like "bounded*0=0" to recursively compute limits like this one.

However, I don't understand existing code enough to know how and where to introduce it. :-/

Concerning atan(), nseries() improvement may help :
atan(1/x).nseries(x, 0, 8)
Traceback (most recent call last):
...
PoleError: Cannot expand around 1/x

In WxMaxima:
(%i6) taylor(atan(1/x), x, 0, 8);
Is  x  positive or negative?p;
(%o6) %pi/2-x+x^3/3-x^5/5+x^7/7+...


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