default(realprecision,38);
s=x+x^2+O(x^5)
f=[atan,asin,acos,cosh,sinh,tanh,acosh,asinh,atanh];
{
for (i=1,#f,
  print(f[i](s));
  print(f[i](O(x^5)));
  print(f[i]([Pol(1)]));
)
}
O(x^-2)
O(1/x^2)
trace(I*x+1+O(x^2))
norm(I*x+1+O(x^2))
a=Ser(vector(200,i,i));
a^2 == a*(a+1) - a \\ test RgX_mullow, RgX_sqrlow
3+O(1)
serreverse(x/2+O(x^2))
serreverse(tan(x)/2)

Ser(x+y+O(x^2),x)
Ser(x+y+O(x^2),y)
Ser("")
