Converse: If $\sim q\ \longrightarrow\ \sim p$ is true, then $p\ \longrightarrow\ q$ is true. Biconditional: $p\ \longrightarrow\ q$ is true if and only if $\sim q\ \longrightarrow\ \sim p$ is true. A conditional and its contrapositive have the same truth value.
Work Step by Step
To write the converse of a conditional statement, write a new conditional statement that switches the hypothesis and conclusion. To write a biconditional, join the hypothesis and the conclusion with the term "if and only if".