Distribution tails of a history-dependent random linear recursion

2022 ◽  
pp. 1-18
Author(s):  
Alexander Roitershtein ◽  
Zirou Zhou
Keyword(s):  
Author(s):  
Carsten Lutz ◽  
Leif Sabellek

We consider ontology-mediated queries (OMQs) based on an EL ontology and an atomic query (AQ), provide an ultimately fine-grained analysis of data complexity and study rewritability into linear Datalog-aiming to capture linear recursion in SQL. Our main results are that every such OMQ is in AC0, NL-complete or PTime-complete, and that containment in NL coincides with rewritability into linear Datalog (whereas containment in AC0 coincides with rewritability into first-order logic). We establish natural characterizations of the three cases, show that deciding linear Datalog rewritability (as well as the mentioned complexities) is ExpTime-complete, give a way to construct linear Datalog rewritings when they exist, and prove that there is no constant bound on the arity of IDB relations in linear Datalog rewritings.


Cybernetics ◽  
1976 ◽  
Vol 11 (5) ◽  
pp. 727-735 ◽  
Author(s):  
V. K. Sabel'fel'd
Keyword(s):  

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