Use a truth table to show that the argument below is valid.
\[\begin{eqnarray}A\to B\\ \overline{\neg B \to \neg A}\end{eqnarray}\]
Use a truth table to show that the argument below is valid.
\[\begin{eqnarray}A\to B\\ \overline{\neg B \to \neg A}\end{eqnarray}\]