On the basis of analysis of the two valued logic simulation and the three valued logic simulation

a new logic system

six valued logic system

is suggested. There exist some disadvantages if the two valued logic simulation is adopted

because the transient state of gate is neglected. There are also some restrictions in three vaclued logic simulation as x = x. As for the six valued logic simulation

these disadvantages can be overcome. It could be said that the two valued logic system is an efficient approach to analyse the behavior of the digital logic system in the steady state

while the six valued logic system is an efficient approach to analyse the bahavior of the digital logic system even if it is in the transient state.