Turing Machines

A TM consists of

    1.    An infinite tape divided into cells.

    2.    A head that reads from and writes to the tape.

    3.    A finite set of internal states.

    4.    A finite alphabet.

The behaviour of the machine is described by a state table

Each move of the machine is of the following form:

    a.    TM is in stateq on cell x

    b.    read b from that cell       

A==   

    c.    write b' to that cell, or

    d.    move Left or Right one cell

    e.    enter state q'

B==

    c.    Halt

The behaviour of the machine is described by a set of quintuples

(initial state, input, action, final state)

e.g.

    (q, b, L, q'), or (q, #, H, q), or ...