Class one cellular automata
Class one cellular automata are those where the development of all patterns tends towards vacuum.
Class one has many similarities to class two cellular automata. It is frequently simple to prove that no growth pattern can exist in a Life-like or closely related cellular automaton. The nonexistence of still lifes or oscillators can be, however, more difficult. As such, it can be difficult to distinguish class two CA whose ash has extremely low density from class one.