\subsection{Traversal Lemmas}
Firstly, some lemmas.
-
\statement{Tip Correct Contents}{
- \tipcy \haspatch \pd
+ \tipcy \haspatch \pa E
\equiv
- \pc = \pd \lor \pc \hasdep \pd
+ \pa E = \pc \lor \pa E \isdep \pc
}
\proof{
- WIP
+ For $\pc = \pa E$, Tip Own Contents suffices.
+ For $\pc \neq \pa E$, Exclusive Tip Contents
+ gives $D \isin \tipcy \equiv D \isin \baseof{\tipcy}$
+ which by Correct Base $\equiv D \isin \tipcn$.
}
\subsection{Base Dependency Merge, Base Sibling Merge}