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Commit da4c8786 authored by Nathan Lhote's avatar Nathan Lhote
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...@@ -20,7 +20,7 @@ ...@@ -20,7 +20,7 @@
\newcommand{\sst}{\textsf{SST}\xspace} \newcommand{\sst}{\textsf{SST}\xspace}
\newcommand{\mtt}{\textsf{MTT}\xspace} \newcommand{\mtt}{\textsf{MTT}\xspace}
\newcommand{\dlin}{\textsc{DLinSpace}} \newcommand{\dlin}{\textsc{DLinSpace}\xspace}
\newcommand{\ssign}{\mathfrak{S}} \newcommand{\ssign}{\mathfrak{S}}
\newcommand{\tsign}{\mathfrak{T}} \newcommand{\tsign}{\mathfrak{T}}
...@@ -132,7 +132,7 @@ It is easy to see that $subsets\in\textsf{ExpF}$. ...@@ -132,7 +132,7 @@ It is easy to see that $subsets\in\textsf{ExpF}$.
Let $T$ be an \msomi of dimension $d$ from structures over $\ssign$ to Let $T$ be an \msomi of dimension $d$ from structures over $\ssign$ to
structures over $\tsign$, and let $\phi(x_1,\dots,x_k)$ be an \fo-formula over structures over $\tsign$, and let $\phi(x_1,\dots,x_k)$ be an \fo-formula over
$\tsign$. $\tsign$.
We can define an \mso-formula $\psi(\bar X_1,\ldots,\bar X_k)$ such that for any structure $A$ over $\ssign$, $A\models\psi(\bar S_1,\ldots,\bar S_k) $ if and only if $\sem T(A)\models \phi(\bar S_1,\ldots,\bar S_k)$.\footnote{Note that $\bar S_i$ is a position of the structure $\sem T(A)$} We can define an \mso-formula $\psi(\bar X_1,\ldots,\bar X_k)$ such that for any structure $A$ over $\ssign$, $A\models\psi(\bar S_1,\ldots,\bar S_k) $ if and only if $\sem T(A)\models \phi(\bar S_1,\ldots,\bar S_k)$.\footnote{Note that $\bar S_i$ denotes either a tuple of sets of positions of $A$, or a position of $\sem T(A)$}
\end{theorem} \end{theorem}
\begin{proof} \begin{proof}
...@@ -160,10 +160,11 @@ Does $\msot\circ \msomi \subseteq \msomi$ hold? Using Krohn-Rhodes theorem of Mi ...@@ -160,10 +160,11 @@ Does $\msot\circ \msomi \subseteq \msomi$ hold? Using Krohn-Rhodes theorem of Mi
\begin{question} \begin{question}
Given a (fixed) \msomi realizing $f$, can one compute the image of a word $u$ in time $O(|u|+|f(u)|)$ ? Given a (fixed) \msomi realizing $f$, can one compute the image of a word $u$ in time $O \big( |u|+|f(u)|\big)$ ?
\end{question} \end{question}
\subsection{Closure properties} \subsection{Closure properties}
\subsubsection{Postcomposition by \foi}
\begin{theorem} \begin{theorem}
$\foi\ \circ \msomi\ = \msomi$ $\foi\ \circ \msomi\ = \msomi$
\end{theorem} \end{theorem}
...@@ -178,6 +179,16 @@ From the backward translation theorem. ...@@ -178,6 +179,16 @@ From the backward translation theorem.
\end{proof} \end{proof}
\subsubsection{Precomposition by \msot}
\begin{theorem}
$\msomi\ \circ \msot\ = \msomi$
\end{theorem}
\begin{proof}
From the usual proof of closure under composition of \msot.
\end{proof}
\subsection{\Expreg functions of polynomial growth} \subsection{\Expreg functions of polynomial growth}
...@@ -195,7 +206,7 @@ From the backward translation theorem. ...@@ -195,7 +206,7 @@ From the backward translation theorem.
\section{The case of the successor} \section{The case of the successor}
\begin{theorem} \begin{theorem}
\msomi with successor is equivalent to \dlin \msomi with successor is equivalent to \dlin reductions.
\end{theorem} \end{theorem}
\begin{proof} \begin{proof}
......
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