lim log(-1 + x) x->0+
pi*I
= (-7.22489922557688e-34 + 3.14159265358979j)
lim log(-1 + x) x->0-
= (9.54288936740968e-30 + 3.14159265358979j)
(-7.22489922557688e-34 + 3.14159265358979j)