Extension of Mayer's theorems to gases with many-particle forces

Mayer diagram technique for the case of classical non-ideal gas with arbitrary multiparticle forces is analysed. A version of the proof of the 1-st Mayer theorem (connectedness of the logarithm of statistical sum) and the second Mayer theorem (star-like form of all graphs in the virial expansion) is proposed, which is valid for systems with multiparticle forces.