From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 4 Aug 2013 17:02:02 +0000 (+0100)
Subject: notation: clarify git merge notations
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=topbloke-formulae.git;a=commitdiff_plain;h=f3f813bac72c13ef2284335346d02443d2f09f87

notation: clarify git merge notations
---

diff --git a/article.tex b/article.tex
index 82e7428..59ae0eb 100644
--- a/article.tex
+++ b/article.tex
@@ -5,6 +5,7 @@
 \usepackage{mathabx}
 \usepackage{txfonts}
 \usepackage{amsfonts}
+\usepackage{eufrak}
 \usepackage{mdwlist}
 %\usepackage{lastpage}
 %\usepackage{accents}
@@ -39,6 +40,8 @@
           \hidehacktrue\ifhidehack#1\else#2\fi\hidehackfalse}
         \newcommand{\pa}[1]{\hidefromedef{\varmathbb{#1}}{#1}}
 
+\newcommand{\stmt}[1]{\mathfrak{#1}}
+
 \newcommand{\set}[1]{\mathbb{#1}}
 \newcommand{\pay}[1]{\pa{#1}^+}
 \newcommand{\pan}[1]{\pa{#1}^-}
@@ -86,7 +89,7 @@
 \newcommand{\pendsof}[2]{\pends ( #1 , #2 ) }
 
 %\newcommand{\commitmerge}{\text{\commitmergename}}
-\newcommand{\commitmergeof}[4]{#1 \approx \stmtmergeof{#2}{#3}{#4}}
+\newcommand{\commitmergeof}[4]{#1 \has \stmtmergeof{#2}{#3}{#4}}
 %\newcommand{\merge}[4]{{#2 {{\frac{ #1 }{ #3 } #4}}}}
 \newcommand{\commitmergename}{Git Merge}
 
diff --git a/notation.tex b/notation.tex
index 19cf243..929fece 100644
--- a/notation.tex
+++ b/notation.tex
@@ -86,32 +86,33 @@ the relevant Topbloke branches, we hope that
 if the user still cares about the Topbloke patch,
 git's merge algorithm will DTRT when trying to re-apply the changes.
 
-\item[ $\displaystyle \stmtmergeof{L}{M}{R} $ ]
+\item[ $\displaystyle \stmtmergeof{\stmt L}{\stmt M}{\stmt R} $ ]
 The proper results of a merge.  Formally,
-where $L$, $M$ and $R$ are statements:
+where $\stmt L$, $\stmt M$ and $\stmt R$ are statements:
 $$
-  \stmtmergeof{L}{M}{R}
+  \stmtmergeof{\stmt L}{\stmt M}{\stmt R}
     \equiv
   \begin{cases}
-         (L \land R)      : & \true \\
-    (\neg L \land \neg R) : & \false \\
-    \text{otherwise} : & \neg M
+         (\stmt L \land \stmt R)      : & \true \\
+    (\neg \stmt L \land \neg \stmt R) : & \false \\
+    \text{otherwise} : & \neg \stmt M
   \end{cases}
 $$
 
-May also be used where $L$, $M$ and $R$ are sets, in which case
+May also be used with sets:
 $$
-  \setmergeof{L}{M}{R}
+  \setmergeof{\set L}{\set M}{\set R}
      =
   \left\{
     \;
     D \; \middle| \;
-      \setmergeof{ D \in L }{ D \in M }{ D \in R }
+      \setmergeof{ D \in \set L }{ D \in \set M }{ D \in \set R }
     \;
   \right\}
 $$
 
 \item[ $\displaystyle \commitmergeof{C}{L}{M}{R} $ ]
+With $C$, $L$, $M$ and $R$ being commits, a convenience notation.
 $C$ has exactly the contents of a git merge result:
 
 $\displaystyle D \isin C \equiv
@@ -121,6 +122,6 @@ $\displaystyle D \isin C \equiv
   \end{cases}
 $
 
-We will refer to this as \commitmergename.
+We will refer to this as \bf\commitmergename.
 
 \end{basedescript}