b.)\\
\hspace{-0.09cm}\scalebox{0.85}{
	\begin{dplltabular}{4}
		\dpllStep{1|2|3|4}
		\dpllDecL{0|1|2|3}
		\dpllAssi{ - |$\lnot a$|$\lnot a, \lnot b$|$\lnot a, \lnot b, \lnot c$}
		\dpllClause{1}{$\lnot a, b$}{$\lnot a, b$|\done|\done|\done}
		\dpllClause{2}{$\lnot a, \lnot d$}{$\lnot a, \lnot d$|\done|\done|\done}
		\dpllClause{3}{$c, \lnot b$}{$c, \lnot b$|$c, \lnot b$|\done|\done}
		\dpllClause{4}{$\lnot c, d$}{$\lnot c, d$|$\lnot c, d$|$\lnot c, d$|\done}
		\dpllBCP{ - | - | - | - }
		\dpllPL{ - | - | - | - }
		\dpllDeci{$\lnot a$|$\lnot b$|$\lnot c$|SAT}
	\end{dplltabular}
}

