Amos Satterlee

General Definitions

The Grid: the environment of cellular automatoa which is infinite in all directions.

Cell: the basic building unit of The Grid. Unless otherwise explicitly specified, a cell is a square.

Seed: one or more cells in a row which provide the initial condition.

State: the status of a cell before or after the running of a cellular automaton. In the basic cellular automaton, there are two fundamental states. The active state, usually depicted as a black cell, and the inactive state usually depicted as an empty or white cell.

Target cell: the cell whose state is being determined by the cellualr automaton.

Rule: the combination of cells which are referenced in determing the state of a target cell. In the basic cellular automaton, the rules are a combination of the target cell's predecessor and the predecessor's two neighbors. There are eight possible rules ranging from three blank (inactive) predecessor cells to three filled (active) predecessor cells.

Rule state: the condition which a rule will turn a target cell. An active rule will produce an active target cell; an inactive rule will produce an inactive target cell. Each rule can be either active or passive.

Ruleset: a combination of rules with rule states specified. In the basic cellular automaton, there are 256 rulesets.

Result: a group of rulesets which exhibit a consistent behavior. In the basic cellualr automaton, there are sixteen result groups each comprising sixteen rulesets.

Rule notation: #:xxx where # is the rule number and the x's indicate the state of the cells. The symbols represent the same thing in a different way. For instance, Rule 7 is defined as all predecessor cells being active. The notation is 7:111. The notation 7:000 is invalid because it references Rule 7 but all the referenced cells are inactive.

Invoke: what a rule does. The statement "an active rule produces an active target cell" is equivalent to the statement "the rule invokes an active cell". Usually used to specify the rule which produced the state of the target cell.