Partial Fractions Expansion of Cotangent/Proof 1/Historical Note

Historical Note on Partial Fractions Expansion of Cotangent/Proof 1
The original demonstration of the partial fractions expansion of the cotangent function was presented by.

It is non-rigorous, in the sense that it has not at this stage been established that it is in fact possible to perform that expansion of $\cot \pi x$ into such an expansion in the first place.