UNIVERSAL TURING MACHINES
OUTLINE Review Algorithm Why
TURING MACHINES (TM) An infinitely long tape A finite number of states A set of transitions from one state to one state, depending on the character read
REPRESENTING A TM Starting StateSymbol ReadEnding StateSymbol WrittenDirection 1011R 1110R 1∆2∆L
UNIVERSAL TURING MACHINES (UTM) A TM (U) that takes the representation of another TM (M) and the tape that M would process as inputs, and processes the tape as M would.
ALGORITHM - PREPARATION Tape Working Buffer Machine Representation {Initial, Scanned, Final, Written, Direction} Tape Description
ALGORITHM - SUBROUTINES Copier Matcher Substituter
ALGORITHM - EXAMPLE X000000Y Z … X1X Z … X1X Z … X101100Y Z … X Y Z … X Y Z … X Y Z … X Y Z … X Y Z …
ANOTHER MACHINE
WHY? Computability
UTM.pdf