minor additions

git-svn-id: http://svn.cactuscode.org/arrangements/CactusBase/Boundary/trunk@240 6a38eb6e-646e-4a02-a296-d141613ad6c4

1 files changed, 6 insertions, 2 deletions

diff --git a/doc/documentation.tex b/doc/documentation.tex
index e27881f..51ebda7 100644
--- a/doc/documentation.tex
+++ b/doc/documentation.tex
@@ -35,12 +35,16 @@ The general idea is that codes which use boundary conditions, be they
 physical or symmetry conditions, need not know anything about the
 thorns which provide them.
 
+This thorn also contains some standard boundary conditions, most of which 
+can be used with any spatial dimension and data type.
+
 \subsection{Local and non-local boundary conditions}
 
 Boundary conditions can be \emph{local}, meaning that the boundary
 point can be updated based on data in its immediate vicinity, or
 \emph{non-local}, meaning that the new value on the boundary depends
-on data from a remote region of the computational domain.  An example
+on data from a remote region of the computational domain (for a parallel 
+simulation this data could for example be physically located on several different processors).  An example
 of the latter is a ``rotating'' symmetry condition, which arises
 e.g.~when one uses a quadrant to simulate a physical domain which
 possesses a rotational symmetry.
@@ -52,7 +56,7 @@ the computational domain as a subregion of some larger domain which
 possesses symmetries.  These symmetries allow a simulation of the
 subregion to act as an effective simulation of the larger encompassing
 domain, because the latter can be inferred from the former via the
-symmetry.  For example, one can simulate a rotating star by
+symmetry.  For example, one can often simulate a rotating star by
 `slicing' the space in half through the equatorial plane, simulating
 only one half, and placing a reflection boundary condition at this
 plane.  The symmetry can be regarded as a property of the