internal state, what is currently read from the input file, and what is seen by the
read-write head. A schematic representation of an offline machine is shown in
Figure 10.6. A formal definition of an offline Turing machine is easily made, but
we will leave this as an exercise. What we want to do briefly is to indicate why
the class of offline Turing machines is equivalent to the class of standard
machines.
First, the behavior of any standard Turing machine can be simulated by some
offline model. All that needs to be done by the simulating machine is to copy the
input from the input file to the tape. Then it can proceed in the same way as the
standard machine.
Figure 10.6
Figure 10.7
read-write head. A schematic representation of an offline machine is shown in
Figure 10.6. A formal definition of an offline Turing machine is easily made, but
we will leave this as an exercise. What we want to do briefly is to indicate why
the class of offline Turing machines is equivalent to the class of standard
machines.
First, the behavior of any standard Turing machine can be simulated by some
offline model. All that needs to be done by the simulating machine is to copy the
input from the input file to the tape. Then it can proceed in the same way as the
standard machine.
Figure 10.6
Figure 10.7