Multiple zeta functions constitute a family of complex-valued functions defined by nested series of the form ζ(s₁,s₂,…,sₖ)=∑_{n₁>n₂>⋯>nₖ>0} n₁^{-s₁} n₂^{-s₂}⋯nₖ^{-sₖ}, where the arguments sᵢ are ...