This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Proof method: construction October 5, 2005 6 Equivalent machines M 0 1 ~ ~ ~ ~ ~ ~ a a a ~ ~ ~ ~ ~ a b ~ ~ ~ ~ ~ ~ # 1 # a a a # a b # ~ ~ S October 5, 2005 7 Simulating ktape behavior • Single tape start string is #w#~ #...#~ # • Each move proceeds as follows: – Start at leftmost slot – Scan right to (k+1) st # to find symbol at each virtual tape head – Make second pass making updates indicated by ktape transition function – When a virtual head moves onto a #, shift string to right October 5, 2005 8 Corollary Corollary: A language is Turingrecognizable if and only if some multitape Turing machine recognizes it. October 5, 2005 9 Example • Using 2tape Turing machine, write a copy machine • Copy tape 1 to tape 2 • Move tape 1 to beginning • Copy tape 1 to tape 2 • Accept...
View
Full
Document
 Spring '11
 sm
 Transition function, multitape Turing machines

Click to edit the document details