A linear bounded automaton (plural linear bounded automata, abbreviated LBA) is a restricted form of a nondeterministic Turing machine. It possesses a tape made up of cells that can contain symbols from a finite alphabet, a head that can read from or write to one cell on the tape at a time and can be moved, and a finite number of states. It differs from a Turing machine in that while the tape is initially considered to have unbounded length, only...
more
A linear bounded automaton (plural linear bounded automata, abbreviated LBA) is a restricted form of a nondeterministic Turing machine. It possesses a tape made up of cells that can contain symbols from a finite alphabet, a head that can read from or write to one cell on the tape at a time and can be moved, and a finite number of states. It differs from a Turing machine in that while the tape is initially considered to have unbounded length, only a finite contiguous portion of the tape, whose length is a linear function of the length of the initial input, can be accessed by the read/write head. This limitation makes an LBA a more accurate model of computers that actually exist than a Turing machine in some respects.
Linear bounded automata are acceptors for the class of context-sensitive languages. The only restriction placed on grammars for such languages is that no production maps a string to a shorter string. Thus no derivation of a string in a context-sensitive language can...
less
