
6.5.1 Predicate calculus
Problem:
Reduce the predicate logic formula to prenex normal form. Is the formula on the set \( M=\{1,2\} \) : 1) satisfiable, 2) refutable, 3) generally valid, 4) unsatisfiable? Calculate the truth value of the formula on the set \( M \) with the following predicates:
\begin{tabular}{|c|c|c|}
\hline\( x \) & 1 & 2 \\
\hline\( P(x) \) & 1 & 0 \\
\hline\( R(x) \) & 0 & 1 \\
\hline
\end{tabular}
\begin{tabular}{|c|c|c|}
\hline\( Q(x, y) \) & 1 & 2 \\
\hline 1 & 1 & 0 \\
\hline 2 & 0 & 0 \\
\hline
\end{tabular}
\[
\forall x P(x) \rightarrow(R(x) \rightarrow \exists y Q(x, y)) \text {. }
\]