X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=topbloke-formulae.git;a=blobdiff_plain;f=article.tex;h=4e4a75e3da95ab850d6d64d180225ebc41c8fbc0;hp=e8f44b514c2f188281bc8f0a4ad985d6c10377fc;hb=6ee81e455482807431ddfb06b9045e01d0fc9da1;hpb=e699df403adb72f770cc724de5e6e4128d576bb4

diff --git a/article.tex b/article.tex
index e8f44b5..4e4a75e 100644
--- a/article.tex
+++ b/article.tex
@@ -3,14 +3,23 @@
 \usepackage{stmaryrd}
 \usepackage{slashed}
 \usepackage{txfonts}
-\begin{document}
+\usepackage{amsfonts}
+%\usepackage{accents}
+
+\renewcommand{\ge}{\geqslant}
+\renewcommand{\le}{\leqslant}
+
+\newcommand{\has}{\sqsupseteq}
+\newcommand{\isin}{\sqsubseteq}
+
 \newcommand{\nothaspatch}{{%
   \declareslashed{}{\sslash}{-0.04}{0}{\Sqsupset}\slashed{\Sqsupset}}}
-\newcommand{\notinpatch}{{%
+\newcommand{\notpatchisin}{{%
   \declareslashed{}{\sslash}{-0.04}{0}{\Sqsubset}\slashed{\Sqsubset}}}
 \newcommand{\haspatch}{\Sqsupset}
-\newcommand{\inpatch}{\Sqsubset}
+\newcommand{\patchisin}{\Sqsubset}
 
+\newcommand{\set}[1]{\mathbb #1}
 \newcommand{\pa}[1]{\varmathbb #1}
 \newcommand{\pay}[1]{\pa{#1}^+}
 \newcommand{\pan}[1]{\pa{#1}^-}
@@ -19,18 +28,37 @@
 \newcommand{\py}{\pay{P}}
 \newcommand{\pn}{\pan{P}}
 
-sponge
-$ A \sqsubseteq B $
-$ A \not \sqsubseteq B $
-$ A \nsqsubseteq B $
-$ A \Sqsubset B $
-$ A \Sqsupset B $
-$ A \haspatch B $
-$ A \nothaspatch B $
-$ A \inpatch B $
-$ A \notinpatch B $
-$ A \nothaspatch \pa{C} $
-$ A \nothaspatch \py $
-$ A \nothaspatch \p_C^+ $
-$ A \nothaspatch \pan{C} $
+%\newcommand{\hasparents}{\underaccent{1}{>}}
+%\newcommand{\hasparents}{{%
+%  \declareslashed{}{_{_1}}{0}{-0.8}{>}\slashed{>}}}
+\newcommand{\hasparents}{>_{\mkern-7.0mu _1}}
+\newcommand{\areparents}{<_{\mkern-14.0mu _1\mkern+5.0mu}}
+
+\renewcommand{\implies}{\Rightarrow}
+
+\setlength{\parindent}{0pt}
+
+\begin{document}
+
+\section{Notation}
+
+$ C \hasparents \set X $ The parents of commit $C$ are exactly the set
+$\set X$.
+
+$ C \ge D $ $C$ is a descendant of $D$ in the git commit
+graph.  This is a partial order, namely the transitive closure of 
+$ D \in \set X $ where $ C \hasparents \set X $.
+
+$ C \has D $ Informally, the tree at commit $C$ contains the change
+made in commit $D$.  Does not take account of deliberate reversions by
+the user or in non-Topbloke-controlled branches; these are considered
+normal, forward, commits.  For merges and Topbloke-generated
+anticommits, the ``change made'' is only to be thought of as any
+conflict resolution.  This is not a partial order because it is not
+transitive.
+
+\section{Invariants}
+
+No rewind/replay: $ C \has D \implies C \ge D $
+
 \end{document}