O jednoznaczności zasady najmniejszego skrępowania (najmniejszego przymusu) Gaussa

A German scholer P. Stackel has investigated the uniqueness of Gauss' principle for a system with restrained and nonrestrained ideal holonomic and linear nonholonomic constraints of the first order. For a regular position of a system the Gauss' principle determines the motion uniquely, while in a singular case non-uniquely. The subsquent development of the problem can be traced in A. Przeborski's papers who has investigated Gauss' principle for the most general case of holonomic and nonholonomic constraints with friction.