}\]
\[ \eqn{ Merge Ends }{
X \not\haspatch \p \land
- Y \haspatch \p \land
- E \in \pendsof{X}{\py}
- \implies
+ Y \haspatch \p
+ \implies \left[
+ \bigforall_{E \in \pendsof{X}{\py}}
E \le Y
+ \right]
}\]
\subsection{No Replay}
\subsubsection{For (wlog) $X \not\haspatch \p, Y \haspatch \p$:}
-$C \haspatch \p \equiv C \nothaspatch M$.
+$C \haspatch \p \equiv M \nothaspatch \p$.
\proofstarts
-Merge Ends applies.
-
+Merge Ends applies. Recall that we are considering $D \in \py$.
$D \isin Y \equiv D \le Y$. $D \not\isin X$.
-
-Consider $D = C$.
+We will show for each of
+various cases that $D \isin C \equiv M \nothaspatch \p \land D \le C$
+(which suffices by definition of $\haspatch$ and $\nothaspatch$).
+
+Consider $D = C$: Thus $C \in \py, L \in \py$, and by Tip
+Self Inpatch $L \haspatch \p$, so $L=Y, R=X$. By Tip Merge,
+$M=\baseof{L}$. So by Base Acyclic $D \not\isin M$, i.e.
+$M \nothaspatch \p$. And indeed $D \isin C$ and $D \le C$. OK.
+
+Consider $D \neq C, M \nothaspatch P, D \isin Y$:
+$D \le Y$ so $D \le C$.
+$D \not\isin M$ so by $\merge$, $D \isin C$. OK.
+
+Consider $D \neq C, M \nothaspatch P, D \not\isin Y$:
+$D \not\le Y$. If $D \le X$ then
+$D \in \pancsof{X}{\py}$, so by Merge Ends and
+Transitive Ancestors $D \le Y$ --- a contradiction, so $D \not\le X$.
+Thus $D \not\le C$. By $\merge$, $D \not\isin C$. OK.
+
+Consider $D \neq C, M \haspatch P, D \isin Y$:
+$D \le Y$ so $D \le M$
+
+%anyway D \not\isin X
+% D \isin Y
+% D \le Y
+
+%bad case
+% D \not\le M
+% D \not\isin M
+% results
+% D \isin C wrong
+
+%ok case
+% D \le M
+% D \isin M
+% results
+% D \not\isin C OK
\end{document}