In message <[EMAIL PROTECTED]>,
    "Bernie Cosell" writes:

: [...]
: In particular, CSLs are the same as the set of languages computable by 
: Turing machines, so that anything a Turing machine can do can be 
: expressed as a context-senstive language (and vice versa, of course), 
: [...]

You're thinking of the recursively enumerable languages.  An LBA
(linear-bounded automaton--a Turing machine with a tape of length kn,
where n is the length of the input and k is some constant) can be
constructed to recognize any CSL.  You need a Turing machine with an
infinite tape to recognize the r.e. languages, but the kicker is that
the membership problem for r.e. languages is undecidable.

Greg

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