From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Mon, 12 Mar 2012 13:57:35 +0000 (+0000)
Subject: replace various no replay with Ingredients Prohibit Replay
X-Git-Tag: f0.2~66
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=topbloke-formulae.git;a=commitdiff_plain;h=50b998e462f27bb63703b7224ab96faa560c3290

replace various no replay with Ingredients Prohibit Replay
---

diff --git a/article.tex b/article.tex
index 7345312..25b529f 100644
--- a/article.tex
+++ b/article.tex
@@ -293,6 +293,26 @@ by the LHS.  And $A \le A''$.
 }\]
 xxx proof tbd
 
+\[ \eqn{Ingredients Prohibit Replay:}{
+  \left[
+    {C \hasparents \set A} \land
+   \\
+    \left(
+      D \isin C \implies
+       D = C \lor
+       \Largeexists_{A \in \set A} D \isin A
+    \right)
+  \right] \implies \left[
+    D \isin C \implies D \le C
+  \right]
+}\]
+\proof{
+  Trivial for $D = C$.  Consider some $D \neq C$, $D \isin C$.
+  By the preconditions, there is some $A$ s.t. $D \in \set A$
+  and $D \isin A$.  By No Replay for $A$, $D \le A$.  And
+  $A \le C$ so $D \le C$.
+}
+
 \[ \eqn{Totally Foreign Contents:}{
   \bigforall_{C \hasparents \set A}
    \left[
@@ -312,37 +332,6 @@ If $D \neq C$ then $D \le A$ where $A \in \set A$.  By Foreign
 Contents of $A$, $\patchof{D} = \bot$.
 }
 
-\subsection{No Replay for Merge Results}
-
-If we are constructing $C$, with,
-\gathbegin
-  \mergeof{C}{L}{M}{R}
-\gathnext
-  L \le C
-\gathnext
-  R \le C
-\end{gather}
-No Replay is preserved.  \proofstarts
-
-\subsubsection{For $D=C$:} $D \isin C, D \le C$.  OK.
-
-\subsubsection{For $D \isin L \land D \isin R$:}
-$D \isin C$.  And $D \isin L \implies D \le L \implies D \le C$.  OK.
-
-\subsubsection{For $D \neq C \land D \not\isin L \land D \not\isin R$:}
-$D \not\isin C$.  OK.
-
-\subsubsection{For $D \neq C \land (D \isin L \equiv D \not\isin R)
- \land D \not\isin M$:}
-$D \isin C$.  Also $D \isin L \lor D \isin R$ so $D \le L \lor D \le
-R$ so $D \le C$.  OK.
-
-\subsubsection{For $D \neq C \land (D \isin L \equiv D \not\isin R)
- \land D \isin M$:}
-$D \not\isin C$.  OK.
-
-$\qed$
-
 \section{Commit annotation}
 
 We annotate each Topbloke commit $C$ with:
@@ -389,7 +378,8 @@ This also covers Topbloke-generated commits on plain git branches:
 Topbloke strips the metadata when exporting.
 
 \subsection{No Replay}
-Trivial.
+
+Ingredients Prohibit Replay applies.  $\qed$
 
 \subsection{Unique Base}
 If $A, C \in \py$ then by Calculation of Ends for
@@ -490,11 +480,7 @@ Given $L$, create a Topbloke base branch initial commit $B$.
 
 \subsection{No Replay}
 
-If $\patchof{L} = \pa{L}$, trivial by Base Acyclic for $L$.
-
-If $\patchof{L} = \bot$, consider some $D \isin B$.  $D \neq B$.
-Thus $D \isin L$.  So by No Replay of $D$ in $L$, $D \le L$.
-Thus $D \le B$.
+Ingredients Prohibit Replay applies.  $\qed$
 
 \subsection{Unique Base}
 
@@ -578,7 +564,10 @@ is a descendant, not an ancestor, of the 2nd parent.)
 
 \subsection{No Replay}
 
-No Replay for Merge Results applies.  $\qed$
+By definition of $\merge$,
+$D \isin C \implies D \isin L \lor D \isin R^- \lor D = C$.
+So, by Ordering of Ingredients,
+Ingredients Prohibit Replay applies.  $\qed$
 
 \subsection{Desired Contents}
 
@@ -732,7 +721,10 @@ is therefore consistent with our scheme.
 
 \subsection{No Replay}
 
-No Replay for Merge Results applies.  $\qed$
+By definition of $\merge$,
+$D \isin C \implies D \isin L \lor D \isin R \lor D = C$.
+So, by Ingredients,
+Ingredients Prohibit Replay applies.  $\qed$
 
 \subsection{Unique Base}