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)
“Exploitation and oppression is not a matter of race. It is the system, the apparatus of world-wide brigandage called imperialism, which made the Powers behave the way they did. I have no illusions on this score, nor do I believe that any Asian nation or African nation, in the same state of dominance, and with the same system of colonial profit-amassing and plunder, would have behaved otherwise.”
—Han Suyin (b. 1917)