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sav08:classical_decision_problem [2008/04/02 17:14] vkuncak created |
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====== Classical Decision Problem ====== | ====== Classical Decision Problem ====== | ||
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+ | Consider satisfiability problem for sentences in first-order logic. | ||
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+ | Without loss of generality, assume that formulas are in prenex form. | ||
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+ | Classify formulas according to | ||
+ | * presence or absence of equality in formulas | ||
+ | * regular expression describing the sequence of quantifiers (e.g. $\exists^* \forall^*$ means formulas $\forall x_1. \ldots. \forall x_n. \exists y_1.\ldots \exists y_n. F$) | ||
+ | * number and arity of relation symbols | ||
+ | * number and arity of function symbols | ||
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+ | For each such description, determine whether the subsets of formulas that satisfy it are decidable or not. | ||
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+ | Example: the exists-forall class that we will study is denoted | ||
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+ | ===== References ===== | ||
* [[http://www.logic.rwth-aachen.de/pub/graedel/Gr-kalmar03.ps|Decidable Classes of First-Order and Fixpoint Logics]] | * [[http://www.logic.rwth-aachen.de/pub/graedel/Gr-kalmar03.ps|Decidable Classes of First-Order and Fixpoint Logics]] | ||
+ | * [[http://www.di.unipi.it/~boerger/decpblbook.html|Egon Börger, Erich Grädel, Yuri Gurevich: The Classical Decision Problem]], also on [[http://books.google.ch/books?id=3po2Tv_UVcMC&vq=On+the+classical+decision+problem|Google Books]] | ||
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