Answer
\begin{array}{l}{\text { precedes (jefferson, X) }} \\ {X=\text { lincoln }} \\ {X=f d r} \\ {X=\text { kennedy }} \\ {X=\text { nixon }}\end{array}
Work Step by Step
\begin{array}{l}{\text { precedes (jefferson, X) }} \\ {X=\text { lincoln }} \\ {X=f d r} \\ {X=\text { kennedy }} \\ {X=\text { nixon }}\end{array}