Theory
We define a queue machine by the six-tuple
- where
- is a finite set of states;
- is the finite set of the input alphabet;
- is the finite queue alphabet;
- is the initial queue symbol;
- is the start state;
- is the transition function.
We define the current status of the machine by a configuration, an ordered pair of its state and queue contents (note defines the Kleene closure or set of all supersets of ). Therefore the starting configuration on an input string is defined as, and we can define our transition as the function that, given an initial state and queue, takes the function to a new state and queue. Note the "first-in-first-out" property of the queue in the relation
where defines the next configuration relation, or simply the transition function from one configuration to the next.
The machine accepts a string if after a (possibly infinite) number of transitions the starting configuration evolves to exhaust the string (reaching a null string ), or
Read more about this topic: Queue Automaton
Famous quotes containing the word theory:
“... the first reason for psychology’s failure to understand what people are and how they act, is that clinicians and psychiatrists, who are generally the theoreticians on these matters, have essentially made up myths without any evidence to support them; the second reason for psychology’s failure is that personality theory has looked for inner traits when it should have been looking for social context.”
—Naomi Weisstein (b. 1939)
“No theory is good unless it permits, not rest, but the greatest work. No theory is good except on condition that one use it to go on beyond.”
—André Gide (1869–1951)
“... liberal intellectuals ... tend to have a classical theory of politics, in which the state has a monopoly of power; hoping that those in positions of authority may prove to be enlightened men, wielding power justly, they are natural, if cautious, allies of the “establishment.””
—Susan Sontag (b. 1933)