Our analysis of time reversal symmetry of various dynamical equations of fluid dynamics including Boltzmann integro-differential equation reveals that in a good number of cases there are no unique methods to relegate them to the so-called irreversible category unambiguously though they neither can be grouped into the reversible category. This substantiates Professor Santilli's No Reduction Theorem [1-3] that formed a base to develop genomathematics [4]. Hence, we once again substantiate the assertion of Professor Santilli that the only option commensurate with irreversibility and nonequilibrium thermodynamics is Santilli's Lie-Admissible Mechanics.