  We analyze the Sznajd opinion formation model, where a pair of neighboring
individuals sharing the same opinion on a square lattice convince its six
neighbors to adopt their opinions, when a fraction of the individuals is
updated according to the usual random sequential updating rule (asynchronous
updating), and the other fraction, the simultaneous updating (synchronous
updating). This combined updating scheme provides that the bigger the
synchronous frequency becomes, the more difficult the system reaches a
consensus. Moreover, in the thermodynamic limit, the system needs only a small
fraction of individuals following a different kind of updating rules to present
a non-consensus state as a final state.
