\usepackage{stmaryrd}
\usepackage{slashed}
\usepackage{txfonts}
-\usepackage{accents}
+\usepackage{amsfonts}
+%\usepackage{accents}
\renewcommand{\ge}{\geqslant}
\renewcommand{\le}{\leqslant}
\newcommand{\haspatch}{\Sqsupset}
\newcommand{\patchisin}{\Sqsubset}
-\newcommand{\pa}[1]{\mathbb #1}
+\newcommand{\set}[1]{\mathbb #1}
+\newcommand{\pa}[1]{\varmathbb #1}
\newcommand{\pay}[1]{\pa{#1}^+}
\newcommand{\pan}[1]{\pa{#1}^-}
\newcommand{\hasparents}{>_{\mkern-7.0mu _1}}
\newcommand{\areparents}{<_{\mkern-14.0mu _1\mkern+5.0mu}}
+\renewcommand{\implies}{\Rightarrow}
+
+\setlength{\parindent}{0pt}
+
\begin{document}
-sponge
-$ C \hasparents X $
-$ C > X $
-$ X \areparents C $
-$ X < C $
-$ D \isin C $
-$ A \sqsubseteq B $
-$ A \not \sqsubseteq B $
-$ A \nsqsubseteq B $
-$ A \le B $
-$ A \Sqsubset B $
-$ A \Sqsupset B $
-$ A \haspatch B $
-$ A \nothaspatch B $
-$ A \patchisin B $
-$ A \notpatchisin B $
-$ A \nothaspatch \pa{C} $
-$ A \nothaspatch \py $
-$ A \nothaspatch \p_C^+ $
-$ A \nothaspatch \pan{C} $
+\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}