Turing Machine Flashcards
1
Q
what does a turing machine consist of
A
- infinite tape divided into cells
- read/write head
- finite set of states
- transition function
2
Q
explain the following in a turing machine
infinite tape
A
- each cell can hold a single symbol from the finite alphabet
- the tape acts as both the input/output mechanism and tghe memory of the machine
3
Q
explain the following in a turing machine
read/write head
A
- in can read the symbol currently under it, write a new symbol or leave it unchanged
- it can move one cell to the left or right
4
Q
explain the following in a turing machine
finite set of states
A
- the machine has a finite number os states with a start state and one or more halting states
5
Q
explain the following in a turing machine
transition function
A
- determines the machine actions based on the current state and ther symboil being read
6
Q
explain how a turing machine works
A
- start in the initial state with the tape containing the input
- follow the transition rules based on the current state and the symbol under the head
- continue processing symbols and transitioning between states until a halting state is reached
7
Q
what is a universal turing machine
A
- a turing machine that can read the description of another turing machine and its input from its tape
- a single machine that can perform any computation that any other turing machine can perform
8
Q
why can a universal turing machine be cosidered to be more powerful than any computer you can purchase
A
it has an infinte amount of memory
9
Q
How can transition rules be represented in a Turing machine?
A
- Transition Function: A function that maps the current state and symbol under the head to a new state, symbol to write, and direction to move.
Example: (current state, current symbol) → (new state, new symbol, direction) - State Transition Diagram: A graphical representation where:
- States are circles, including start and halting states.
- Transitions are arrows between states, labeled with the symbol that triggers the transition and the new symbol to write.
- Each arrow represents the movement of the head (left or right) after the symbol is written.
10
Q
A