Finite product of complex numbers

Function

definition it $\equiv$ Finite sum over a monoid w.r.t $\langle\!\langle {\mathbb C},\cdot \rangle\!\rangle$

$\prod_{k=1}^n\left(1+\frac{1}{k}\right)=n+1$


Subset of

Finite sum over a monoid

Requirements

Complex number