X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=blobdiff_plain;f=article.tex;h=b7df641e68703266c1729e1c3abf32680e35f805;hb=c132ec1004fa71f8ea8467b659d3f5996089f1dc;hp=28d02a02c7153d08724d0d451ac2fe922024a6b9;hpb=2f6d22b0c5f79efe583c8016b2860474261f4750;p=topbloke-formulae.git diff --git a/article.tex b/article.tex index 28d02a0..b7df641 100644 --- a/article.tex +++ b/article.tex @@ -171,18 +171,6 @@ $\displaystyle D \isin C \equiv \end{cases} $ -Some (overlapping) alternative formulations: - -$\displaystyle D \isin C \equiv - \begin{cases} - D \isin L \equiv D \isin R : & D = C \lor D \isin L \\ - D \isin L \equiv D \isin R : & D = C \lor D \isin R \\ - D \isin L \nequiv D \isin R : & D = C \lor D \not\isin M \\ - D \isin M \equiv D \isin L : & D = C \lor D \isin R \\ - D \isin M \equiv D \isin R : & D = C \lor D \isin L \\ - \end{cases} -$ - \end{basedescript} \newpage \section{Invariants} @@ -211,6 +199,23 @@ We maintain these each time we construct a new commit. \\ \section{Some lemmas} +\[ \eqn{Alternative (overlapping) formulations defining + $\mergeof{C}{L}{M}{R}$:}{ + D \isin C \equiv + \begin{cases} + D \isin L \equiv D \isin R : & D = C \lor D \isin L \\ + D \isin L \nequiv D \isin R : & D = C \lor D \not\isin M \\ + D \isin L \equiv D \isin M : & D = C \lor D \isin R \\ + D \isin L \nequiv D \isin M : & D = C \lor D \isin L \\ + \text{as above with L and R exchanged} + \end{cases} +}\] +\proof{ + Truth table xxx + + Original definition is symmetrical in $L$ and $R$. +} + \[ \eqn{Exclusive Tip Contents:}{ \bigforall_{C \in \py} \neg \Bigl[ D \isin \baseof{C} \land ( D \in \py \land D \le C ) @@ -424,21 +429,27 @@ Used for removing a branch dependency. \subsection{Conditions} +\[ \eqn{ Into Base }{ + L \in \pn +}\] \[ \eqn{ Unique Tip }{ \pendsof{L}{\pry} = \{ R^+ \} }\] \[ \eqn{ Currently Included }{ L \haspatch \pry }\] -\[ \eqn{ Not Self }{ - L \not\in \{ R^+ \} -}\] -\subsection{No Replay} +\subsection{Ordering of ${L, R^+, R^-}$:} By Unique Tip, $R^+ \le L$. By definition of $\base$, $R^- \le R^+$ -so $R^- \le L$. So $R^+ \le C$ and $R^- \le C$ and No Replay for -Merge Results applies. $\qed$ +so $R^- \le L$. So $R^+ \le C$ and $R^- \le C$. + +(Note that the merge base $R^+ \not\le R^-$, i.e. the merge base is +later than one of the branches to be merged.) + +\subsection{No Replay} + +No Replay for Merge Results applies. $\qed$ \subsection{Desired Contents} @@ -476,11 +487,38 @@ $\qed$ \subsection{Unique Base} -Need to consider only $C \in \py$, ie $L \in \py$. +Into Base means that $C \in \pn$, so Unique Base is not +applicable. $\qed$ + +\subsection{Tip Contents} + +Again, not applicable. $\qed$ + +\subsection{Base Acyclic} + +By Base Acyclic for $L$, $D \isin L \implies D \not\in \py$. +And by Into Base $C \not\in \py$. +Now from Desired Contents, above, $D \isin C +\implies D \isin L \lor D = C$, which thus +$\implies D \not\in \py$. $\qed$. -xxx tbd +\subsection{Coherence and Patch Inclusion} -xxx need to finish anticommit +Need to consider some $D \in \py$. By Into Base, $D \neq C$. + +\subsubsection{For $\p = \pr$:} +By Desired Contents, above, $D \not\isin C$. +So $C \nothaspatch \pr$. + +\subsubsection{For $\p \neq \pr$:} +By Desired Contents, $D \isin C \equiv D \isin L$ +(since $D \in \py$ so $D \not\in \pry$). + +If $L \nothaspatch \p$, $D \not\isin L$ so $D \not\isin C$. +So $L \nothaspatch \p \implies C \nothaspatch \p$. + +Whereas if $L \haspatch \p$, $D \isin L \equiv D \le L$. +so $L \haspatch \p \implies C \haspatch \p$. \section{Merge} @@ -539,7 +577,7 @@ Merge Ends condition applies. Good. \subsection{No Replay} -See No Replay for Merge Results. +No Replay for Merge Results applies. $\qed$ \subsection{Unique Base} @@ -613,7 +651,8 @@ So indeed $L \haspatch \p \land R \haspatch \p \implies C \haspatch \p$. \subsubsection{For (wlog) $X \not\haspatch \p, Y \haspatch \p$:} -$C \haspatch \p \equiv M \nothaspatch \p$. +$M \haspatch \p \implies C \nothaspatch \p$. +$M \nothaspatch \p \implies C \haspatch \p$. \proofstarts @@ -706,6 +745,35 @@ $\baseof{C} = R$ so $D \isin C \equiv D \isin \baseof{C}$. OK. $\qed$ -xxx up to here, need to prove other things about merges +\subsection{Foreign Inclusion} + +Consider some $D$ s.t. $\patchof{D} = \bot$. +By Foreign Inclusion of $L, M, R$: +$D \isin L \equiv D \le L$; +$D \isin M \equiv D \le M$; +$D \isin R \equiv D \le R$. + +\subsubsection{For $D = C$:} + +$D \isin C$ and $D \le C$. OK. + +\subsubsection{For $D \neq C, D \isin M$:} + +Thus $D \le M$ so $D \le L$ and $D \le R$ so $D \isin L$ and $D \isin +R$. So by $\merge$, $D \isin C$. And $D \le C$. OK. + +\subsubsection{For $D \neq C, D \not\isin M, D \isin X$:} + +By $\merge$, $D \isin C$. +And $D \isin X$ means $D \le X$ so $D \le C$. +OK. + +\subsubsection{For $D \neq C, D \not\isin M, D \not\isin L, D \not\isin R$:} + +By $\merge$, $D \not\isin C$. +And $D \not\le L, D \not\le R$ so $D \not\le C$. +OK + +$\qed$ \end{document}