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Linear Bounded Automata LBAs. Linear Bounded Automata (LBAs) are the same as Turing Machines with one difference:. The input string tape space is the only tape space allowed to use. Linear Bounded Automaton (LBA). Input string. Working space in tape. Left-end marker. Right-end marker.
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Linear Bounded AutomataLBAs Costas Busch - RPI
Linear Bounded Automata (LBAs) are the same as Turing Machines with one difference: The input string tape space is the only tape space allowed to use Costas Busch - RPI
Linear Bounded Automaton (LBA) Input string Working space in tape Left-end marker Right-end marker All computation is done between end markers Costas Busch - RPI
We define LBA’s as NonDeterministic Open Problem: NonDeterministic LBA’s have same power with Deterministic LBA’s ? Costas Busch - RPI
Example languages accepted by LBAs: LBA’s have more power than NPDA’s LBA’s have also less power than Turing Machines Costas Busch - RPI
The Chomsky Hierarchy Costas Busch - RPI
Unrestricted Grammars: Productions String of variables and terminals String of variables and terminals Costas Busch - RPI
Example unrestricted grammar: Costas Busch - RPI
Theorem: A language is recursively enumerable if and only if is generated by an unrestricted grammar Costas Busch - RPI
Context-Sensitive Grammars: Productions String of variables and terminals String of variables and terminals and: Costas Busch - RPI
The language is context-sensitive: Costas Busch - RPI
Theorem: A language is context sensistive if and only if is accepted by a Linear-Bounded automaton Observation: There is a language which is context-sensitive but not recursive Costas Busch - RPI
The Chomsky Hierarchy Non-recursively enumerable Recursively-enumerable Recursive Context-sensitive Context-free Regular Costas Busch - RPI