Révision 163
CSL17/preliminaries.tex (revision 163) | ||
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%(include closure properties) |
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\begin{definition} |
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Given $i\geq 0$, a language $L$ belongs to the class $\sigp{i}$ off there exists a polynomial time predicate $A$ and a polynomial $q$ such that:
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Given $i\geq 0$, a language $L$ belongs to the class $\sigp{i}$ if there exists a polynomial time predicate $A$ and a polynomial $q$ such that:
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$$ x \in L \Leftrightarrow \exists y_1 \in \{0,1\}^{q(\size{x})}\forall y_2 \in \{0,1\}^{q(\size{x})}\dots Q_iy_i\in \{0,1\}^{q(\size{x})}\ A(x,y_1,\dots,y_i)=1$$ |
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where $Q_i=\forall$ (resp. $Q_i=\exists$) if $i$ is even (resp. odd). |
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... | ... | |
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\end{itemize} |
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\end{definition} |
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One then obtains: |
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\begin{theorem}[\cite{BellantoniThesis}] |
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\begin{theorem}[\cite{BellantoniThesis, Bellantoni95}]
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The class of functions representable by $\mubc$ programs is $\fph$, and for each $i$ the class representable by $\mubc^i$ programs is $\fphi{i}$. |
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\end{theorem} |
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We will also need an intermediary lemma, also proved in \cite{BellantoniThesis}. |
CSL17/ph-biblio.bib (revision 163) | ||
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pages = {97--110}, |
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year = {1992} |
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} |
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@inproceedings{Bellantoni95, |
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author = {Stephen Bellantoni}, |
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title = {Predicative Recursion and The Polytime Hierarchy}, |
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booktitle = {Feasible Mathematics II}, |
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pages = {15-29}, |
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series = {Progress in Computer Science and Applied Logic}, |
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volume = {13}, |
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editors ={Clote P., Remmel J.B.}, |
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publisher = {Birkhauser Boston}, |
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year = {1995} |
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} |
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@inproceedings{Cobham, |
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author = {Cobham, A.}, |
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title = {On the intrinsic computational difficulty of functions}, |
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