For each operation called for by the traversal algorithms, we prove
that the commit generation preconditions are met.
+WIP WHAT ABOUT PROVING ALL THE TRAVERSAL RESULTS
+
+\subsection{Base Dependency Merge, Base Sibling Merge}
+
+We do not prove that the preconditions are met. Instead, we check
+them at runtime. If they turn out not to be met, we abandon
+\alg{Merge-Base} and resort to \alg{Recreate-Base}.
+
+TODO COMPLETE MERGE-BASE STUFF
+
+WIP WHAT ABOUT PROVING ALL THE TRAVERSAL RESULTS
+
+\subsection{Recreate Base Beginning}
+
+WHAT IF $\pendsof{L}{\pqy} \neq \{\}$ ?
+
\subsection{Tip Base Merge}
$L = W$, $R = \tipcn$.