Pan-Xu conjecture and reduction formulas for polylogarithms

The objective of the paper is the study of Mneimneh-like sums with a parametric variant of the multiple harmonic-star values. We generalize and resolve the Pan-Xu conjecture on generalized Mneimneh-like sums and present their transformation. As an application, we deduce new reduction formulas for specific multiple polylogarithms enabling lowering their depth, and provide additional findings on arithmetic means of multiple harmonic-star values, resulting in new representations of arbitrary multiple zeta-star values.