\hspace{-0.09cm}\scalebox{0.87}{ \begin{dplltabular}{7} \dpllStep{1|2|3|4|5|6|7} \dpllDecL{0|1|2|2|2|2|1} \dpllAssi{-| $\lnot a$| $\lnot a, \lnot b$| $\lnot a, \lnot b, c$| $\lnot a, \lnot b, c, \lnot e$| $\lnot a, \lnot b, c, \lnot e, \lnot d$| $\lnot a$} \dpllClause{1}{$\lnot a,\lnot c$} {$\lnot a,\lnot c$|\done|\done|\done|\done|\done|\done} \dpllClause{2}{$b,c$} {$b,c$|$b,c$|$c$|\done|\done|\done|$b,c$} \dpllClause{3}{$\lnot b, \lnot d$} {$\lnot b,\lnot d$|$\lnot b,\lnot d$|\done|\done|\done|\done|$\lnot b,\lnot d$} \dpllClause{4}{$\lnot d, e$} {$\lnot d,e$|$\lnot d,e$|$\lnot d,e$|$\lnot d,e$|$\lnot d$|\done|$\lnot d,e$} \dpllClause{5}{$d, e$} {$d.e$|$d.e$|$d.e$|$d.e$|$d$|\conflict|$d,e$} \dpllClause{6}{$a, \lnot c, \lnot e$} {$a, \lnot c, \lnot e$|$\lnot c,\lnot e$|$\lnot c, \lnot e$|$\lnot e$|\done|\done|$\lnot c, \lnot e$} \dpllClause{7}{$\lnot b, c, d$} {$\lnot b,c,d$|$\lnot b,c,d$|\done|\done|\done|\done|$\lnot b,c,d$} \dpllClause{8}{\textcolor{gray}{$a.b$}} {-|-|-|-|-|$a,b$|$b$} \dpllClause{9}{\textcolor{gray}{$a$}} {-|-|-|-|-|-|-} \dpllBCP{-|-|$c$|$\lnot e$|\lnot d|-|$b$} \dpllPL{-|-|-|-|-|-|-} \dpllDeci{$\lnot a$|$\lnot b$|-|-|-|-|-} \end{dplltabular} } First Conflict in Step 6: \\ \begin{conflictgraph} \node[base node] (notA) {$\lnot a$}; \node[base node] (notB) [below of=notA] {$\lnot b$}; \node[base node] (C) [right of=notB] {$c$}; \node[base node] (notE) [above right of=C] {$\lnot e$}; \node[base node] (D) [above right of=notE] {$d$}; \node[base node] (notD) [below right of=notE] {$\lnot d$}; \node[base node] (bot) [below right of=D] {$\bot$}; \path[] (notA) edge [] node {$6$} (notE) (notB) edge [] node {$2$} (C) (C) edge [] node {$6$} (notE) (notE) edge [] node {$4$} (D) (notE) edge [] node {$5$} (notD) (notD) edge [] node {} (bot) (D) edge [] node {} (bot); \end{conflictgraph} \begin{prooftree} \AxiomC{$4. \; \lnot d \lor e$} \AxiomC{$5. \; d \lor e$} \BinaryInfC{$e$} \AxiomC{$6. \; a \lor \lnot c \lor \lnot e$} \BinaryInfC{$a \lor \lnot c$} \AxiomC{$2. \; b \lor c$} \BinaryInfC{$ a \lor b$} \end{prooftree} \vspace{1cm} \scalebox{0.87}{ \begin{dplltabular}{8} \dpllStep{8|9|10|11|12|13|14} \dpllDecL{1|1|1|1|0|0|0} \dpllAssi{ $\lnot a, b$| $\lnot a, b, \lnot d$| $\lnot a, b, \lnot d, c$| $\lnot a, b, \lnot d, c, \lnot e$| -| $a$| $a, \lnot c$} \dpllClause{1}{$\lnot a,\lnot c$} {\done|\done|\done|\done|$\lnot a,\lnot c$|$\lnot c$|\done} \dpllClause{2}{$b,c$} {\done|\done|\done|\done|$b,c$|$b,c$|$b$} \dpllClause{3}{$\lnot b, \lnot d$} {$\lnot d$|\done|\done|\done|$\lnot b,\lnot d$|$\lnot b,\lnot d$|$\lnot b,\lnot d$} \dpllClause{4}{$\lnot d, e$} {$\lnot d,e$|\done|\done|\done|$\lnot d,e$|$\lnot d,e$|$\lnot d,e$} \dpllClause{5}{$d, e$} {$d,e$|$e$|$e$|\conflict|$d,e$|$d,e$|$d,e$} \dpllClause{6}{$a, \lnot c, \lnot e$} {$\lnot c,\lnot e$|$\lnot c,\lnot e$|$\lnot e$|\done|$a, \lnot c, \lnot e$|\done|\done} \dpllClause{7}{$\lnot b, c, d$} {$d,c$|$c$|\done|\done|$\lnot b, c, d$|$\lnot b, c, d$|$\lnot b, d$} \dpllClause{8}{\textcolor{gray}{$a.b$}} {\done|\done|\done|\done|$a,b$|\done|\done} \dpllClause{9}{\textcolor{gray}{$a$}} {-|-|-|$a$|$a$|\done|\done} \dpllBCP{$\lnot d$|$c$|$\lnot e$|-|$a$|$\lnot c$|$b$} \dpllPL{-|-|-|-|-|-|-} \dpllDeci{-|-|-|-|-|-|-} \end{dplltabular} } Second Conflict in Step 11: \\ \begin{conflictgraph} \node[base node] (notA) {$\lnot a$}; \node[base node] (B) [right of=notA] {$b$}; \node[base node] (notD) [right of=B] {$\lnot d$}; \node[base node] (E) [right of=notD] {$e$}; \node[base node] (C) [below of=E] {$c$}; \node[base node] (notE) [right of=C] {$\lnot e$}; \node[base node] (bot) [above right of=notE] {$\bot$}; \path[] (notA) edge [] node {$8$} (B) (B) edge [] node {$3$} (notD) (notD) edge [] node {$5$} (E) (notD) edge [] node {$7$} (C) (C) edge [] node {$6$} (notE) (notE) edge [] node {} (bot) (E) edge [] node {} (bot); \end{conflictgraph} \begin{prooftree} \AxiomC{$6. \; a \lor \lnot c \lor \lnot e$} \AxiomC{$7. \; \lnot b \lor c \lor d$} \BinaryInfC{$a \lor \lnot b \lor d \lor \lnot e$} \AxiomC{$5. \; d \lor e$} \BinaryInfC{$a \lor \lnot b \lor d$} \AxiomC{$3. \; \lnot b \lor \lnot d$} \BinaryInfC{$ a \lor \lnot b$} \AxiomC{$8. \; a \lor b$} \BinaryInfC{$a$} \end{prooftree} \vspace{1cm} \scalebox{0.87}{ \begin{dplltabular}{2} \dpllStep{15|16} \dpllDecL{0|0} \dpllAssi{$a, \lnot c, b$| $a, \lnot c, b, \lnot d$} \dpllClause{1}{$\lnot a,\lnot c$} {\done|\done} \dpllClause{2}{$b,c$} {\done|\done} \dpllClause{3}{$\lnot b, \lnot d$} {$\lnot d$|\done} \dpllClause{4}{$\lnot d, e$} {$\lnot d,e$|\done} \dpllClause{5}{$d, e$} {$d,e$|$e$} \dpllClause{6}{$a, \lnot c, \lnot e$} {\done|\done} \dpllClause{7}{$\lnot b, c, d$} {$d$|\conflict} \dpllClause{8}{\textcolor{gray}{$a.b$}} {\done|\done} \dpllClause{9}{\textcolor{gray}{$a$}} {\done|\done} \dpllBCP{$\lnot d$|-} \dpllPL{-|-} \dpllDeci{-|UNSAT} \end{dplltabular} } Second Conflict in Step 16: \\ \begin{conflictgraph} \node (0) {}; \node[base node] (A) [right of=0] {$a$}; \node[base node] (notC) [right of=A] {$\lnot c$}; \node[base node] (B) [right of=notC] {$b$}; \node[base node] (notD) [right of=B] {$\lnot d$}; \node[base node] (D) [below of=notD] {$d$}; \node[base node] (bot) [above right of=D] {$\bot$}; \path[] (0) edge [] node {$9$} (A) (A) edge [] node {$1$} (notC) (notC) edge [] node {$2$} (B) (B) edge [] node {$3$} (D) (B) edge [] node {$7$} (notD) (notD) edge [] node {} (bot) (D) edge [] node {} (bot); \end{conflictgraph} \begin{prooftree} \AxiomC{$7. \; \lnot b \lor c \lor d$} \AxiomC{$3. \; \lnot b \lor \lnot d$} \BinaryInfC{$\lnot b \lor c$} \AxiomC{$2. \; b \lor c$} \BinaryInfC{$c$} \AxiomC{$1. \; \lnot a \lor \lnot c$} \BinaryInfC{$\lnot a$} \AxiomC{$9. \; a$} \BinaryInfC{$\bot$} \end{prooftree}