\newcommand{\dpllDescription}[1]{Use the DPLL algorithm with conflict-driven clause learning to determine whether or not the set of clauses given is satisfiable. Decide variables in alphabetical order starting with the \textit{#1} phase. For conflicts, draw conflict graphs after the end of the table, and add the learned clause to the table.\\ If the set of clauses resulted in \texttt{SAT}, give a satisfying model. If the set of clauses resulted in \texttt{UNSAT}, give a resolution proof that shows that the conjunction of the clauses from the table is unsatisfiable.} \newcommand{\dpllDescriptionAssignmentSheet}{Use the DPLL algorithm with the rules as described above to check whether the following formula in CNF is satisfiable} \newcommand{\ndDescription}{ For each of the following sequents, either provide a natural deduction proof, or a counter-example that proves the sequent invalid. \\ \noindent For proofs, clearly indicate which rule, and what assumptions/premises/\\intermediate results you are using in each step. Also clearly indicate the scope of any boxes you use. \\ \noindent For counterexamples, give a complete model. Show that the model satisfies the premise(s) of the sequent in question, but does not satisfy the respective conclusion.} \newcommand{\tseitinRules}{% We list the \emph{Tseitin-rewriting rules} to be applied for the following examples. \begin{align*} \chi \leftrightarrow (\phi \lor \psi) \quad &\Leftrightarrow \tseitinOr{\chi}{\phi}{\psi} \\ \chi \leftrightarrow (\phi \land \psi) \quad &\Leftrightarrow \tseitinAnd{\chi}{\phi}{\psi} \\ \chi \leftrightarrow \lnot \phi \quad &\Leftrightarrow \tseitinNot{\chi}{\phi} \end{align*} } \newcommand{\constructROBDD}[2]{% Construct the reduced and ordered BDD for the formula% $$#1$$% using #2. Compute the needed cofactors. You may add function nodes representing all cofactors to the final BDD. Use complemented edges and one terminal node representing the truth value $\T$. To simplify drawing, you may assume that dangling edges point to the constant node.} \newcommand{\BDDToROBDD}{% Transform the given Binary Decision Diagram into a reduced and ordered BDD.} \newcommand{\BDDToDNF}{% Given the following Binary Decision Diagram that represents the formula $f$. Compute its disjunctive normal form \DNF{f}.} \newcommand{\computeCNFDNF}[1][\varphi]{% Compute \DNF{#1} and \CNF{#1} using a truth table. } \newcommand{\CNFfromCircuit}{% Compute the propositional formula $\varphi$ represented by the following circuit. Furthermore, compute an equisatisfiable formula $\varphi'$ using the Tseitin transformation. } \newcommand{\applyTseitin}[1]{% Apply the Tseitin transformation to #1. For each variable you introduce, clearly indicate which subformula it represents. } \newcommand{\applyCC}[1]{% Consider the following formula in the conjunctive fragment of $\mathcal{T}_{EUF}$. #1 Use the congruence closure algorithm to determine whether this formula is satisfiable. } \newcommand{\applyAckermann}[1]{% Given the formula #1 Apply the Ackermann reduction to compute an equisatisfiable formula in $\mathcal{T}_{E}$. } \newcommand{\applyGB}[1]{% Perform the graph-based reduction to translate the following formula in $\mathcal{T}_{E}$ into an equisatisfiable formula in propositional logic. #1 } \newcommand{\applyEagerEUF}[1]{% Consider the following formula in $\mathcal{T}_{EUF}$. #1 \begin{itemize} \item Use Ackermann's reduction to compute an equisatisfiable formula in $\mathcal{T}_{E}$. \item Then perform the graph-based reduction on the outcome of Ackermann's reduction to construct an equisatisfiable propositional formula $\phi_{prop}$. \end{itemize} }