A tag system is a deterministic computational model published by Emil Leon Post in 1943 as a simple form of Post canonical system. A tag system may also be viewed as an abstract machine, called a Post tag machine (not to be confused with Post-Turing machines)—briefly, a finite state machine whose only tape is a FIFO queue of unbounded length, such that in each transition the machine reads the symbol at the head of the queue, deletes a fixed number of symbols from the head, and to the tail appends a symbol-string preassigned to the deleted symbol. (Because all of the indicated operations are performed in each transition, a tag machine strictly has only one state.)
Read more about Tag System: Definition, Turing-completeness of m-tag Systems, The 2-tag Halting Problem, Historical Note On The Definition of Tag System, Cyclic Tag Systems, Emulation of Tag Systems By Cyclic Tag Systems
Famous quotes containing the words tag and/or system:
“I believe in the flesh and the appetites,
Seeing, hearing, feeling, are miracles, and each part and tag of me
is a miracle.
Divine am I inside and out, and I make holy whatever I touch or am touch’d from,
The scent of these arm-pits aroma finer than prayer,
This head more than churches, bibles, and all the creeds.”
—Walt Whitman (1819–1892)
“I have no concern with any economic criticisms of the communist system; I cannot enquire into whether the abolition of private property is expedient or advantageous. But I am able to recognize that the psychological premises on which the system is based are an untenable illusion. In abolishing private property we deprive the human love of aggression of one of its instruments ... but we have in no way altered the differences in power and influence which are misused by aggressiveness.”
—Sigmund Freud (1856–1939)