Turing machines. Algorithms. Church-Turing thesis.

250 Pages·2012·5.21 MB·English

A Finite Automaton
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SlidesmodifiedbyBennyChor,basedonoriginalslidesbyMauriceHerlihy,BrownUniversity. –p.1
A Pushdown Automaton
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push
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A Turing Machine
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SlidesmodifiedbyBennyChor,basedonoriginalslidesbyMauriceHerlihy,BrownUniversity. –p.3
Alan Turing (1912–1954)
http://www.turing.org.uk/turing/index.html
SlidesmodifiedbyBennyChor,basedonoriginalslidesbyMauriceHerlihy,BrownUniversity. –p.4
at any point in a computation, only a finite
portion of tape has been accessed.
tape initially contains input string, followed by
blanks ( s).
machine can read from and write on tape
(storage device).
machine can move its “head” both left and right
on tape.
machine halts in either accept or reject states.
machine can also run forever, never halting.
A Turing Machine (TM)
uses infinite tape for its memory.
SlidesmodifiedbyBennyChor,basedonoriginalslidesbyMauriceHerlihy,BrownUniversity. –p.5
tape initially contains input string, followed by
blanks ( s).
machine can read from and write on tape
(storage device).
machine can move its “head” both left and right
on tape.
machine halts in either accept or reject states.
machine can also run forever, never halting.
A Turing Machine (TM)
uses infinite tape for its memory.
at any point in a computation, only a finite
portion of tape has been accessed.
SlidesmodifiedbyBennyChor,basedonoriginalslidesbyMauriceHerlihy,BrownUniversity. –p.5
machine can read from and write on tape
(storage device).
machine can move its “head” both left and right
on tape.
machine halts in either accept or reject states.
machine can also run forever, never halting.
A Turing Machine (TM)
uses infinite tape for its memory.
at any point in a computation, only a finite
portion of tape has been accessed.
tape initially contains input string, followed by
blanks ( s).
SlidesmodifiedbyBennyChor,basedonoriginalslidesbyMauriceHerlihy,BrownUniversity. –p.5
machine can move its “head” both left and right
on tape.
machine halts in either accept or reject states.
machine can also run forever, never halting.
A Turing Machine (TM)
uses infinite tape for its memory.
at any point in a computation, only a finite
portion of tape has been accessed.
tape initially contains input string, followed by
blanks ( s).
machine can read from and write on tape
(storage device).
SlidesmodifiedbyBennyChor,basedonoriginalslidesbyMauriceHerlihy,BrownUniversity. –p.5
machine halts in either accept or reject states.
machine can also run forever, never halting.
A Turing Machine (TM)
uses infinite tape for its memory.
at any point in a computation, only a finite
portion of tape has been accessed.
tape initially contains input string, followed by
blanks ( s).
machine can read from and write on tape
(storage device).
machine can move its “head” both left and right
on tape.
SlidesmodifiedbyBennyChor,basedonoriginalslidesbyMauriceHerlihy,BrownUniversity. –p.5
machine can also run forever, never halting.
A Turing Machine (TM)
uses infinite tape for its memory.
at any point in a computation, only a finite
portion of tape has been accessed.
tape initially contains input string, followed by
blanks ( s).
machine can read from and write on tape
(storage device).
machine can move its “head” both left and right
on tape.
machine halts in either accept or reject states.
SlidesmodifiedbyBennyChor,basedonoriginalslidesbyMauriceHerlihy,BrownUniversity. –p.5