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Formal definition of alternative logarithic space turing machine

In barak and arora and other references I found the formal definition for alternative machines and NL but there is no formal definition for AL. NL definition : there is a read only tape for input and ...
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Relationship of the P=PSPACE problem to alternating complexity classes

From a very naive point of view of someone who haven't studied complexity theory in depth, I am wondering whether the theorems that APSPACE=EXPTIME and AP=PSPACE have any derived results on separating ...
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651 views

canonical complete problems for $\Delta^P_n$

Finding whether or not a QBF can be satisfied is a canonical complete problem for both $\Sigma^P_n$ (start from $\exists$) and $\Pi^P_n$ (start from $\forall$). What is the canonical complete problem ...
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Collapsing of exptime and alternation bounded turing machine

This question was already asked on math overflow, but I did not find any answer to my question (or let say the answer was that up to the knowledge of those people, no answer were known) Let C be a ...
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846 views

Space alternating hierarchy

It is known thanks to Immerman and Szelepcsényi that ${\rm NSPACE}(f)={\rm coNSPACE}(f)$ if $f=\Omega(\log)$ (even for non-space constructible functions). In the same paper, Immerman state that the ...