The f and g functions
The f function defines whether input messages are acceptable:
f is a function: 2X x S -> {0,1} where 2X is the power set of input X. If f({x1,...,xm}, s) is 1, then the cell accepts the input set {x1,...,xm} and x1,...,xm are removed from the output lists of those cells that produce these output messages. The removal of messages is an atomic action which
will occur simultaneously. If f({x1,...,xm}, s) is 0, the input messages are not accepted. When several input sets can be accepted, one is chosen non-deterministically.
The g function defines output cells, output messages, next state and actions:
g is a function: 2X x S -> 2ICB x Y x S x A such that given input messages {x1,...,xm} which have been accepted, i.e., f({x1,...,xm},s) = 1, and current state s, g(x,s) is a quadruple (Ic, y, s', a).