-\section{Traversal phase --- proofs}
-
-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 $\pendsof{L}{\pqy} \neq \{\}$ ?
-FIX BY CHANGE PRECOND OF CREATE BASE
-
-\subsection{Tip Base Merge}
-
-$L = W$, $R = \tipcn$.
-
-TODO TBD
-
-Afterwards, $\baseof{W} = \tipcn$.
-
-\subsection{Tip Source Merge}
-
-In fact, we do this backwards: $L = S$, $R = W$. Since $S \in \pcy$,
-the resulting $C \in \pcy$ and the remaining properties of the Merge
-commit construction are symmetrical in $L$ and $R$ so this is fine.
-
-By the results of Tip Base Merge, $\baseof{W} = \tipcn$.
-
-By Base Ends Supreme, $\tipcn \ge \baseof{S}$ i.e.
-$\baseof{R} \ge \baseof{L}$.
-
-Either $\baseof{L} = \baseof{M}$, or we must choose a different $M$ in
-which case $M = \baseof{S}$ will suffice.
-