∫Vnt1z1-1⁢t2z2-1⁢⋯⁢tnzn-1⁢ⅆ⁡t1⁢ⅆ⁡t2⁢⋯⁢ⅆ⁡tn=Γ⁡z1⁢Γ⁡z2⁢⋯⁢Γ⁡znΓ⁡1+z1+z2+…+zn,