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)
“The twentieth-century artist who uses symbols is alienated because the system of symbols is a private one. After you have dealt with the symbols you are still private, you are still lonely, because you are not sure anyone will understand it except yourself. The ransom of privacy is that you are alone.”
—Louise Bourgeois (b. 1911)