X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=topbloke-formulae.git;a=blobdiff_plain;f=notation.tex;h=48ea1b7e2ceec9002f67b2d41335e5c227b69f25;hp=413305fd86341add556b5d0eec37265e0dab4919;hb=c497f56e8a7f09c4c328bd7560631d8773b7e676;hpb=ab5ce6ebd6f3fa445d336f659a6861205ef2564c

diff --git a/notation.tex b/notation.tex
index 413305f..48ea1b7 100644
--- a/notation.tex
+++ b/notation.tex
@@ -1,4 +1,7 @@
-\section{Notation}
+\stdsection{Notation}
+
+Throughout, any free variables are implicitly universally quantified
+at the outermost level.
 
 \begin{basedescript}{
 \desclabelwidth{5em}
@@ -27,10 +30,19 @@ A patch $\p$ consists of two sets of commits $\pn$ and $\py$, which
 are respectively the base and tip git branches.  $\p$ may be used
 where the context requires a set, in which case the statement
 is to be taken as applying to both $\py$ and $\pn$.
-All of these sets are disjoint.  Hence:
+All of these sets will be disjoint by construction
+(see Invariants, below).  Hence:
+
+\item[ $\foreign$ ]
+The set of all commits which are not part of a Topbloke branch.  We
+call these foreign commits.
+
+\item[ $\set A$, $\set P$, $\ldots$ ]
+Arbitrary sets of commits.  Maybe $\set P = \p$ i.e.\ some $\py$ or $\pn$, but
+maybe not.
 
 \item[ $ \patchof{ C } $ ]
-Either $\p$ s.t. $ C \in \p $, or $\bot$.
+Either $\p$ s.t. $ C \in \p $, or $\foreign$.
 A function from commits to patches' sets $\p$.
 
 \item[ $ \pancsof{C}{\set P} $ ]