You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 

71 lines
3.7 KiB

DPLL algorithm:
\scalebox{1}{
\begin{tabular}{|l|c|c|c|c|c|c|c|c|}
\hline
Step & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 \\ \hline \hline
Decision Level & 0 & 0 & 0 & 1 & 1 & 0 & 0 & 0 \\ \hline
Assignment & - & $\lnot a$ & $\lnot a,c$ & $\lnot a,b,c$ & $\lnot a,b,c,e$ & - & $\lnot b$ & $\lnot b, f$ \\ \hline
Cl. 1: $\lnot a,d$ & 1 & \cmark & \cmark & \cmark & \cmark & 1 & 1 & 1 \\ \hline
Cl. 2: $\lnot d,c$ & 2 & 2 & \cmark & \cmark & \cmark & 2 & 2 & 2 \\ \hline
Cl. 3: $\lnot b,e$ & 3 & 3 & 3 & $e$ & \cmark & 3 & \cmark & \cmark \\ \hline
Cl. 4: $\lnot b,\lnot e$ & 4 & 4 & 4 & $\lnot e$ & $\{\}$ \xmark & 4 & \cmark & \cmark \\ \hline
Cl. 5: $b,f$ & 5 & 5 & 5 & \cmark & \cmark & 5 & $f$ & \cmark \\ \hline
Cl. 6: $b,\lnot f$ & 6 & 6 & 6 & \cmark & \cmark & 6 & $\lnot f$ & $\{\}$ \xmark \\ \hline
\textcolor{gray}{Cl. 7: $\lnot b$} & - & - & - & - & learned $\lnot b$ & 7 & \cmark & \cmark \\ \hline \hline
BCP & - & - & - & $e$ & - & $\lnot b$ & $f$ & - \\ \hline
PL & $\lnot a$ & $c$ & - & - & - & - & - & - \\ \hline
Decision & - & - & $b$ & - & - & - & - & UNSAT \\ \hline
\end{tabular}}
Ad 5:
\begin{center}
\begin{tikzpicture}[->,>=stealth',shorten >=1pt,auto,node distance=1.5cm,
thick,base node/.style={circle,draw,minimum size=20pt}, real node/.style={double,circle,draw,minimum size=20pt}]
\node[base node] (1) {$b$};
\node[base node] (2) [above right of=1] {$e$};
\node[base node] (3) [below right of=1] {$\lnot e$};
\node[base node] (4) [above right of=3] {$\bot$};
\path[]
(1) edge [] node {$3$} (2)
edge [] node {$4$} (3)
(2) edge [] node {} (4)
(3) edge [] node {} (4);
\end{tikzpicture}
\end{center}
\begin{prooftree}
\AxiomC{$3. \; \lnot b \lor e$}
\AxiomC{$4. \; \lnot b \lor \lnot e$}
\BinaryInfC{$\lnot b$}
\end{prooftree}
Ad 8:
\begin{center}
\begin{tikzpicture}[->,>=stealth',shorten >=1pt,auto,node distance=1.5cm,
thick,base node/.style={circle,draw,minimum size=20pt}, real node/.style={double,circle,draw,minimum size=20pt}]
\node (0) {};
\node[base node] (1) [right of=0] {$\lnot b$};
\node[base node] (2) [above right of=1] {$f$};
\node[base node] (3) [below right of=1] {$\lnot f$};
\node[base node] (4) [above right of=3] {$\bot$};
\path[]
(0) edge [] node {$7$} (1)
(1) edge [] node {$5$} (2)
edge [] node {$6$} (3)
(2) edge [] node {} (4)
(3) edge [] node {} (4);
\end{tikzpicture}
\end{center}
\begin{prooftree}
\AxiomC{$5. \; b \lor f$}
\AxiomC{$6. \; b \lor \lnot f$}
\BinaryInfC{$b$}
\AxiomC{$7. \; \lnot b$}
\BinaryInfC{$\bot$}
\end{prooftree}