lim acos(-1 + z) z->z0+
Limit(acos(-1 + z), z, z0)
/ ______________ \ pi | / 2 | -- + I*log\\/ - z0 + 2*z0 - I + I*z0/ 2
lim acos(-1 + z) z->z0+
/ ______________ \ pi | / 2 | -- + I*log\\/ - z0 + 2*z0 - I + I*z0/ 2
lim acos(-1 + z) z->z0-
/ ______________ \ pi | / 2 | -- + I*log\\/ - z0 + 2*z0 - I + I*z0/ 2
pi/2 + i*log(sqrt(-z0^2 + 2*z0) - i + i*z0)