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diff --git a/macros/latex/contrib/blkarray/README b/macros/latex/contrib/blkarray/README
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+blkarray -- extensions and modifications of tabular support
+
+This package is even less supported than any of David Carlisle's other
+packages. It was written a long time ago, and is still documented using
+the conventions of LaTeX2.09 (although it appears to work with current
+LaTeX releases).
+
+In 2014 it had a minor update to work with LaTeX2e font initialisation
+and in 2015 a second update to avoid a clash with amsmath's use of box0.
+
+Apart from these couple of lines all the code dates back to 1992 and
+was more of a thought experiment than production code.
+However people seem to find uses for it.
+
+It is not really a package for using in documents in
+its present state, but if you are interested in coding tables of
+various sorts in TeX, you may be interested to experiment with it...
diff --git a/macros/latex/contrib/blkarray/blkarray.pdf b/macros/latex/contrib/blkarray/blkarray.pdf
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index 0000000000..3281ebe5ca
--- /dev/null
+++ b/macros/latex/contrib/blkarray/blkarray.pdf
diff --git a/macros/latex/contrib/blkarray/blkarray.sty b/macros/latex/contrib/blkarray/blkarray.sty
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+%%%     blkarray.sty
+%%%
+%%% Copyright David Carlisle 1992 1999
+%%%           d.p.carlisle "at" gmail.com
+%%%
+%%% This file may be distributed under the terms of the LPPL.
+%%% See 00readme.txt for details.
+%%%
+%%% Version 0.01 - 0.03  November 1992
+%%% Version 0.04         03 December 1992
+%%% Version 0.05         24 March 1999  (email update only)
+%%% Version 0.06         16 October 2014  Update for LaTeX2e
+%%% Version 0.07         27 February 2015  Update for amsmath
+%%%
+%%%
+%%%
+%%%     A LaTeX style option extending array and tabular
+%%%     HIGHLY VOLATILE, use at your own risk!!!!!!!!
+%%%
+%%%
+%%% 
+%%% ====================================================================
+%
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%<*x>
+% This file may be used without modification as a style (.sty) file.
+%
+% If you have Mittelbach's doc.sty, this file may be formatted with a
+% command like:
+%                latex blkarray.sty
+%
+% If you have the Mittelbach/Duchier/Braams docstrip utility, you may
+% produce a faster loading .sty file. Rename this file to: blkarray.doc
+% Then run this file through *plain* TeX:
+%                tex blkarray.doc
+% This should produce the file blkarray.sty.
+% If you do not have plain TeX on your system, you can trick LaTeX into
+% doing the work as follows:
+%                latex \def\fmtname{plain} \input blkarray.doc
+% Note that you may need to quote the arguments here to stop your
+% operating system treating the \ characters incorrectly.
+%
+%                latex blkarray.doc
+% Will produce a typeset version of the documentation, as above.
+%
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\def\plain{plain}\ifx\fmtname\plain\csname fi\endcsname
+     \def\batchfile{blkarray.doc}
+     \input docstrip
+     \preamble
+
+     Do not distribute the stripped version of this file.
+     The checksum in the header refers to the documented version.
+
+     \endpreamble
+     \generateFile{blkarray.sty}{t}{\from{blkarray.doc}{}}
+     \endinput
+\fi
+%
+\ifcat a\noexpand @\let\next\relax\else\def\next{%
+    \documentclass{article}\usepackage{blkarray,doc}\MakePercentIgnore}\fi\next
+%
+%\def\eatmodule<#1>{}\eatmodule
+%</x>
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% \let\osmall\small\def\small{\osmall\tt}
+% \textwidth=355pt   ^^A Allow macrocode text with 72 columns.
+% \CodelineIndex     ^^A Code lines numbered.
+% \DisableCrossrefs  ^^A No Cross references.
+% \MakeShortVerb{\"} ^^A "\foo" works like \verb+\foo+
+%
+% \title{blkarray.sty}
+% \author{D. P. Carlisle}
+% \begin{document}
+% \maketitle
+%
+% \begin{center}
+% \huge\bf Warning\,!
+% \end{center}
+% \begin{quote}
+% This style option is in the early stages of development. If you want
+% to use an extended {\tt array} or {\tt tabular} in a document,
+% consider using one of the options in the ARRAY package, available from
+% most \TeX-servers.
+%
+% The commands defined in this style are quite likely to have both their
+% user-interface, and their internal definitions changed in later
+% versions.
+% \end{quote}
+%
+%\BAextrarowheight=1pt
+%\BAextraheightafterhline=2pt
+%
+% \section{Introduction}
+% This style option implements an environment, {\tt blockarray}, that
+% may be used in the same way as the {\tt array} or {\tt tabular}
+% environments of standard \LaTeX, or their extended versions defined in
+% {\tt array.sty}. If used in math-mode, {\tt blockarray} acts like
+% {\tt array}, otherwise it acts like {\tt tabular}.
+%
+% The main feature of this style is that it uses a new method of
+% defining column types. In the simplest form, this has been given a
+% syntax matching the "\newcolumntype" command of {\tt array.sty}.\\
+% "\BAnewcolumntype{C}{>{\large}c}"\\
+% defines a column of large centred text.
+%
+% In {\tt array.sty} column specifiers defined via "\newcolumntype" are
+% re-written in a preliminary stage to the primitive types, which are
+% then treated by a completely different mechanism (basically a nested
+% "\if" testing each token against one of the predefined column types,
+% "c", "l", ">", \ldots
+%
+% In {\tt blockarray.sty}, {\em all\/} column specifiers have equal
+% standing, most of the specifiers of Lamport's original are defined
+% using "\BAnewcolumntype", e.g.\\
+% "\BAnewcolumntype{c}   {>{\hfil}<{\hfil}}"
+%
+% There are one or two other features built into {\tt blockarray}, these
+% will be introduced in no particular order.
+%
+% \subsection{Explicit Column Separators in the Preamble}
+%
+% As described in the \LaTeX\ book, originally specifiers like "|" and
+% "@"-expressions were always considered to be part of the {\em
+% preceding\/} column (except for expressions before the first column).
+% This can be inconvenient if that column type is going to be over
+% ridden by a "\multicolumn" specification, consider:
+%
+% \begin{minipage}{3in}
+% \begin{verbatim}
+% \begin{tabular}{c|c|c}
+%  11 & 22                    & 33 \\
+%  1  &\multicolumn{1}{l|}{2} &  3 \\
+%  11 & 22                    & 33
+% \end{tabular}
+% \end{verbatim}
+% \end{minipage}
+% \begin{tabular}{c|c|c}
+%  11 & 22                    & 33 \\
+%  1  &\multicolumn{1}{l|}{2} &  3 \\
+%  11 & 22                    & 33
+% \end{tabular}
+%
+% The rule needs to be specified again in the "\multicolumn" argument as
+% "{l|}", {\tt blockarray} lets you move the rule into the third column,
+% by specifying "&" in the preamble like so:
+%
+% \begin{minipage}{3in}
+% \begin{verbatim}
+% \begin{blockarray}{c|c&|c}
+%  11 & 22                     & 33 \\
+%  1  &\BAmulticolumn{1}{l}{2} &  3 \\
+%  11 & 22                     & 33
+% \end{blockarray}
+% \end{verbatim}
+% \end{minipage}
+% \begin{blockarray}{c|c&|c}
+%  11 & 22                     & 33 \\
+%  1  &\BAmulticolumn{1}{l}{2} &  3 \\
+%  11 & 22                     & 33
+% \end{blockarray}
+%
+% I first came across the idea of having such a feature in an array
+% preamble when  Rainer Sch\"opf gave a brief introduction to various
+% enhanced array styles. An implementation by Denys Duchier had a
+% feature like this, however I have not seen that style so I do not know
+% the details.
+%
+% \subsection{Blocks}
+% Sometimes you want whole blocks of the table to have a different
+% format, this is often the case with headings for instance. This can be
+% accomplished using lots of "\multicolumn" commands, but this style
+% lets you specify the format for such a block in the usual syntax for
+% column specifiers:
+%
+% \begin{minipage}{3in}
+% \begin{verbatim}
+% \begin{blockarray}{*{3}{c}}
+%  11 & 22 & 33 \\
+%  1  & 2  &  3 \\
+% \begin{block}{*{3}{>{\bf}l}}
+%  11 & 22 & 33 \\
+%  1  & 2  & 3  \\
+% \end{block}
+%  1  & 2  &  3
+% \end{blockarray}
+% \end{verbatim}
+% \end{minipage}
+% \begin{blockarray}{*{3}{c}}
+%  11 & 22 & 33 \\
+%  1  & 2  &  3 \\
+% \begin{block}{*{3}{>{\bf}l}}
+%  11 & 22 & 33 \\
+%  1  & 2  & 3  \\
+% \end{block}
+%  1  & 2  &  3
+% \end{blockarray}
+%
+% \subsection{Delimiters}
+%
+% People often want to put delimiters around sub-arrays of a larger
+% array, delimiters can now be specified in the preamble argument:
+%
+% \begin{minipage}{3in}
+% \begin{verbatim}
+% \begin{blockarray}{[cc]c\}}
+%  11 & 22  & 33 \\
+%  1  & 2   &  3 \\
+% \begin{block}{(ll)l\}}
+%  11 & 22 & 33 \\
+%  1  & 2  & 3  \\
+% \end{block}
+%  1  & 2   &  3
+% \end{blockarray}
+% \end{verbatim}
+% \end{minipage}
+% \begin{blockarray}{[cc]c\}}
+%  11 & 22  & 33 \\
+%  1  & 2   &  3 \\
+% \begin{block}{(ll)l\}}
+%  11 & 22 & 33 \\
+%  1  & 2  & 3  \\
+% \end{block}
+%  1  & 2   &  3
+% \end{blockarray}
+%
+% Note how in the previous example the nested {\tt block} was not
+% spanned by the $[\ ]$. each section of the `outer' block was
+% separately bracketed. If instead of the {\tt block} environment we use
+% {\tt block*}, then the outer brackets will span the inner block,
+% however it is not possible to specify any delimiters in the argument
+% of {\tt block*}.
+%
+% \begin{minipage}{3in}
+% \begin{verbatim}
+% \begin{blockarray}{[cc]c\}}
+%  11 & 22  & 33 \\
+%  1  & 2   &  3 \\
+% \begin{block*}{lll}
+%  11 & 22 & 33 \\
+%  1  & 2  & 3  \\
+% \end{block*}
+%  1  & 2   &  3
+% \end{blockarray}
+% \end{verbatim}
+% \end{minipage}
+% \begin{blockarray}{[cc]c\}}
+%  11 & 22  & 33 \\
+%  1  & 2   &  3 \\
+% \begin{block*}{lll}
+%  11 & 22 & 33 \\
+%  1  & 2  & 3  \\
+% \end{block*}
+%  1  & 2   &  3
+% \end{blockarray}
+%
+% The delimiters, "( ) [ ] \{ \}" have been pre-defined as column
+% specifiers,
+% however any delimiter, including these ones can be specified using the
+% specifiers "\Left" and "\Right"\\
+% "\Left{"\meta{text}"}{"\meta{delimiter}"}"\\
+% specifies a delimiter together with a `label' which will be vertically
+% centred with respect to the block. Note that the delimiter and the
+% label take up no horizontal space, and so extra space must be left
+% with a "!"- or "@"-expression or the text will over-print adjacent
+% columns.
+%
+% \subsection{Automatic Numbering}
+% A column specifier "\BAenum" specifies that the row number is to be
+% printed (in a "!"-expression) at that point in each row, this number
+% may be accessed with "\label" in the usual way. The number is a
+% standard \LaTeX\ counter, "BAenumi", and so the appearence may be
+% changed by altering the default definition of "\theBAenumi".
+%
+% \subsection{Footnotes}
+% The "\footnote" command may be used inside {\tt blockarray}.
+% Two styles are supported. If the test "BAtablenotes" is true (by
+% default, or after "\BAtablenotestrue") then footnotes will appear at
+% the end of the table, with lines set to the width of the table. If
+% "BAtablenotes" is false, footnotes within the table will be treated as
+% standard footnotes, with the text (usually) appearing at the foot of
+% the page.
+%
+% If table notes are being set, the footnote counter is reset at the
+% start of the table. Also an extended version of "\footnotetext" can be
+% used. As described in the book, "\footnotetext[2]{xxx}" will produce a
+% text marked with the footnote symbol for `2'. However for tablenotes,
+% the optional argument may also be any non-numeric text, in which case
+% it is set directly at the start of the footnote text. So you can  go
+% "\footnotetext[\sc source:]{xxx}" or "\footnotetext[\sc note:]{xxx}"
+% anywhere in the table body, before the first numbered footnote.
+%
+% If "BAtablenotes" is false the footnote text will not appear at the
+% foot of the page if the whole {\tt blockarray} environment is in an
+% environment which treats footnotes in a special way (eg another {\tt
+% blockarray}). So if you have a complicated table which requires
+% tablenotes, but for \TeX{}nical reasons you wish to enter it in the
+% {\tt .tex} file as nested {\tt blockarray} environments, you may set
+% "\BAtablenotestrue" for the outer environment, and then locally set it
+% to false before each of the nested environments. This will ensure that
+% footnotes from all parts of the table will be collected together at
+% the end.
+%
+% This table is set with "\BAtablenotestrue".
+%
+% \begin{center}
+% \begin{blockarray}{||c||c|||}
+%   ONE\footnotetext[\sc source:]{Chicago Manual of Style.}
+% &
+%   TWO\footnote{Note on TWO. This is a reasonably long footnote, to
+%   show the line breaking.}
+% \\
+%   \begin{blockarray}{|ll|}
+%     \footnotetext[\sc source:]{Chicago Manual of Style.}^^A
+%     \footnotetext[\sc note:]{The above attribution is incorrect.}^^A
+%     l-one & l-two \\
+%     l-three\footnote{Footnote to l-three.} & l-four \\
+%   \end{blockarray}
+% &
+%   \begin{blockarray}{|ll|}
+%     \footnotetext[\sc source:]{Chicago Manual of Style.}^^A
+%     \footnotetext[\sc note:]{The above attribution is incorrect.}^^A
+%     r-one & r-two \\
+%     r-three\footnote{Footnote to r-three} & r-four \\
+%   \end{blockarray}
+% \\
+% THREE\footnote{Note on THREE.} & FOUR \\
+% \end{blockarray}
+% \end{center}
+%
+% In this example, the outer table is set with "\BAtablenotestrue", but
+% each of the inner tables is set with a local setting
+% "\BAtablenotesfalse".
+%
+% Also the footnotes have been set in a single paragraph. Tablenotes
+% will be set `run in' a paragraph, after a "\BAparfootnotes"
+% declaration.
+% \begin{center}
+%
+% \BAparfootnotes
+% \begin{blockarray}{||c||c|||}%
+%   \footnotetext[\sc source:]{Chicago Manual of Style.}^^A
+%   \footnotetext[\sc note:]{The above attribution is incorrect.}^^A
+%   ONE
+% &
+%   TWO\footnote{Note on TWO. This is a reasonably long footnote, to
+%   show the line breaking.}
+% \\\BAtablenotesfalse
+%   \begin{blockarray}{|ll|}
+%     l-one & l-two \\
+%     l-three\footnote{Footnote to l-three.} & l-four \\
+%   \end{blockarray}
+% &
+%   \BAtablenotesfalse
+%   \begin{blockarray}{|ll|}
+%     r-one & r-two \\
+%     r-three\footnote{Footnote to r-three} & r-four \\
+%   \end{blockarray}
+% \\
+% THREE\footnote{Note on THREE.} & FOUR\\
+% \end{blockarray}
+% \end{center}
+%
+% \subsection{Non Aligned Material}
+%
+% The primitive "\noalign" command may be used with standard \LaTeX\
+% arrays, but paragraphs inside "\noalign" are broken into lines that
+% are the width of the page, (or at least the current value of "\hsize")
+% not to the final width of the table. Within a {\tt blockarray}
+% "\BAnoalign" specifies material to be packaged into a parbox the same
+% width as the table. This makes a `hole' in the current block.
+% "\BAnoalign*" is similar, but any delimiters in the current block span
+% across the non-aligned paragraphs.
+%
+% \begingroup
+% \catcode`\Z=0
+% \begin{verbatim}
+% \begin{blockarray}{\BAenum!{.\quad}cc\Right{\}}{\tt block 1}}
+% \BAnoalign*{Zldots The paragraphs Zldots}
+% \begin{block}{\BAenum!{.\quad}(rr\Right{\}}{{\tt block 2} Zdots}}
+% \begin{block*}{\BAenum!{.\quad}(ll)}
+% \begin{block}{\BAenum!{.\quad}>{\bf}l\{c\Right{\}}{\tt block 3}}
+% \BAmultirow{50pt}{Zldots Spanning Zldots}
+% \begin{block}{\BAenum!{.\quad}\{l\}l\Right{\}}{\tt block 4}}
+% \BAnoalign{\centering Unlike  Zldots}
+% \end{verbatim}
+% \endgroup
+%
+% \begin{blockarray}{\BAenum!{.\quad}cc\Right{\}}{\tt block 1}}
+% ccc &cc\\
+% c &ccccccccc \\
+% \BAnoalign*{\raggedright
+% The paragraphs in a {\tt\bslash BAnoalign*} are set to the final width
+% of the table.}
+% \begin{block}{\BAenum!{.\quad}(rr\Right
+%               {\}}{{\tt block 2}, with a nested \tt block*}}
+% rrr&rr \\
+% rrr&r \\
+% \begin{block*}{\BAenum!{.\quad}ll}
+% lll&ll \\
+% l&lll \\
+% \end{block*}
+% r&r \\
+% \end{block}
+% ccc \\
+% \begin{block}{\BAenum!{.\quad}>{\bf}l\{c\Right{\}}{\tt block 3}}
+% LLL&
+% \BAmultirow{50pt}{\centering
+% Spanning all the rows in a block.}
+%  \\
+% LL&  \\
+% L&  \\
+% \end{block}
+% \begin{block}{\BAenum!{.\quad}\{l\}l\Right{\}}{\tt block 4}}
+% ll &l\\
+% \BAnoalign{\centering
+% Unlike {\tt\bslash BAnoalign*}, {\tt\bslash BAnoalign} breaks  any
+% delimiters in the current block.}
+% l&lll \\
+% \end{block}
+% c&c
+% \end{blockarray}
+%
+%
+% \bigskip
+%
+% \subsection{Spanning Rows and Columns}
+%
+% The previous table had an example of the use of a "\BAmultirow"
+% command. If an entry contains\\
+% "\BAmultirow{"\meta{dimen}"}{"\meta{par-mode material}"}"\\
+% then the \meta{par-mode material} will appear in a box at least
+% \meta{dimen} wide, spanning all the rows in the current block. If the
+% other entries in that column of the current block are not empty, they
+% will be over printed by the spanning text.
+%
+% There is a column specification corresponding to "\BAmultirow". if\\
+% "\BAmultirow{"\meta{dimen}"}"\\
+% appears in the preamble, then each entry in that column will be
+% packaged as a paragraph, in a box at least \meta{dimen} wide, spanning
+% all the rows in the current block. If this is the last column in the
+% block, you can not use the optional argument to "\\", and no entry in
+% the column must be empty, it must at least have "{}" in it. (If you
+% need to ask why, you don't want to know!)
+%
+% Similarly there is a column specification corresponding to
+% "\BAmulticolumn".  if\\
+% "\BAmulticolumn{"\meta{number}"}{"\meta{column specification}"}"\\
+% appears in the preamble to a {\tt block}, then the rows in the block
+% should have less entries than the outer block, the  columns
+% will line up as expected.
+%
+% \begin{verbatim}
+% \begin{blockarray}{r|lccr|c}
+% aaa&bbb&ccc&ddd&eee&fff\\
+% \begin{block}{(r|\BAmulticolumn{4}{>{\bf}l}|c)}
+% 111&The second entry in each &333\\
+% \end{block}
+% a&b&c&d&e&f\\
+% \begin{block}{[r|lccr\{\BAmultirow{1in}]}
+% 111&222&333&444&555&Each entry\\
+% 1&2&3&4&5&in this column is packaged as a paragraph.\\
+% 1&2&3&4&5&\relax\\
+% \end{block}
+% a&b&c&d&e&f
+% \end{blockarray}
+% \end{verbatim}
+%
+% \begin{blockarray}{r|lccr|c}
+% aaa&bbb&ccc&ddd&eee&fff\\
+% a&b&c&d&e&f\\
+% \begin{block}{(r|\BAmulticolumn{4}{>{\bf}l}|c)}
+% 111&The second entry in each &333\\
+% 1&row of this block spans 4 &3\\
+% 1&columns of the {\tt blockarray}.&3\\
+% \end{block}
+% a&b&c&d&e&f\\
+% a&b&c&d&e&f\\
+% \begin{block}{[r|lccr\{\BAmultirow{1in}]}
+% 111&222&333&444&555&Each entry\\
+% 1&2&3&4&5&\hbadness10000 in this column is packaged as a paragraph.\\
+% 1&2&3&4&5&\relax\\
+% 1&2&3&4&5&\relax\\
+% 1&2&3&4&5&\relax\\
+% \end{block}
+% a&b&c&d&e&f
+% \end{blockarray}
+%
+% \subsection{Horzontal Lines}
+% For  technical reasons (explained in the code section) the
+% standard "\hline" does not work with "blockarray". "\BAhline" may be
+% used in just the same way, although currently it is implemented
+% using\ldots\\
+% "\BAhhline". The "\hhline" from "hhline.sty", would work, but this is
+% a new implementation, more in the spirit of this style.
+%
+% \begin{minipage}{3in}
+% \begin{verbatim}
+% \begin{blockarray}{||c||c&|cc||cc||}
+% \BAhhline{|t:=:t:=&|==#==:t|}
+% 0&  1  & 2   &  3 &4&5\\
+% \BAhline
+% 0&  1  & 2   &  3&4&5\\
+% \BAhline\BAhline
+% 0&  1  & 2   &  3&4&5\\
+% \BAhhline{||-||-..||.-}
+% 0&  1  & 2   &  3&4&5\\
+% \BAhhline{=::=""::"=}
+% 0&  1  & 2   &  3&4&5\\
+% \BAhhline{|b:=:b:=""::"=:b|}
+% \end{blockarray}
+% \end{verbatim}
+% \end{minipage}
+% \begin{blockarray}{||c||c&|cc||cc||}
+% \BAhhline{|t:=:t:=&|==#==:t|}
+% 0&  1  & 2   &  3 &4&5\\
+% \BAhline
+% 0&  1  & 2   &  3&4&5\\
+% \BAhline\BAhline
+% 0&  1  & 2   &  3&4&5\\
+% \BAhhline{||-||-..||.-}
+% 0&  1  & 2   &  3&4&5\\
+% \BAhhline{=::=""::"=}
+% 0&  1  & 2   &  3&4&5\\
+% \BAhhline{|b:=:b:=""::"=:b|}
+% \end{blockarray}
+%
+% Both "\hline" and "\hhline" increase the (minimum) height of the
+% following row by "\BAextraheightafterhline", which defaults to 0pt.
+% {\tt array.sty} introduced a parameter, known in this style as
+% "\BAextrarowheight", which is a length added to the default height of
+% {\em all\/} the rows. One of the stated reasons for introducing this
+% was to stop horizontal lines touching large entries like accented
+% capitals, however increasing all the row heights has an effect rather
+% similar to setting "\arraystretch". This style allows the the extra
+% height just to be added after the horizontal rule.
+%
+% \subsection{Further Thoughts}
+% \begin{itemize}
+% \item
+% The main point of any environment based on "\halign" is to make
+% entries line up. Using this style as currently implemented, it is easy
+% to spoil this alignment by putting different "@" expressions or rules
+% in the same column in different blocks. In practice, if you want
+% different "@" expressions, you need to do boxing tricks to make sure
+% that they all have the same width. This could be done automatically by
+% the "\halign", if the "@"-expressions and rules were put in a separate
+% column. (This fact could be hidden from the user, by a method similar
+% to the multicolumn column specification).
+%
+% \item
+% The "[tcb]" optional argument does not really work at present, I have
+% not done a proper implementation, as I do not know what to do about
+% horizontal rules.
+%
+% Standard \LaTeX\ lines "[t]" and "[b]" up like this:
+% xx
+% \setbox0=\hbox{\begin{tabular}[t]{|c|}1\\2\\3\end{tabular}}\copy0\
+% xx
+% \setbox2=\hbox{\begin{tabular}[b]{|c|}1\\2\\3\end{tabular}}\copy2\
+% xx
+%
+% However if there are horizontal lines, it looks like:
+% xx
+% \setbox4=\hbox{\begin{tabular}[t]{|c|}\hline1\\2\\3\end{tabular}}^^A
+% \copy4\
+% xx
+% \setbox6=\hbox
+%  {\begin{tabular}[b]{|c|}1\\2\\3\\\hline\end{tabular}}\copy6\
+% xx
+%
+% I {\em think\/} I want it to look like this:
+% xx
+% \dimen0\dp4
+% \advance\dimen0-\dp0
+% \raise\dimen0 \box4\
+% xx
+% \dimen0\ht6
+% \advance\dimen0-\ht2
+% \lower\dimen0 \box6\
+% xx
+%
+% This would be reasonably easy to achieve in a `full' {\tt blockarray},
+% as each row is taken off and inspected, however I would like an array
+% that only uses the features of the original implementation to be
+% processed by the `quick' system. Any ideas?
+%
+% \item
+% Many user-level commands and parameters defined in this style are
+% named "\BA"\ldots\ This is to avoid clashes with the standard
+% environments, especially if these are nested inside {\tt blockarray}.
+% If {\tt array} and {\tt tabular} were re-defined in terms of {\tt
+% blockarray}, many commands could be renamed, for example,
+% "\BAextrarowheight", "\BAmulticolumn", "\BAhline".
+%
+% \item
+% This style uses a lot of macros, and every use of the {\tt blockarray}
+% uses a lot more. Does it work at all on a PC?
+%
+% \end{itemize}
+%
+%
+% \typeout{End of the Introduction and Examples.}
+% \typein[\answer]%
+%   {Do you want an annotated listing of the macro definitions (y/n) ?}
+% \def\next{y}\ifx\answer\next\else\expandafter\stop\fi
+%
+
+% \clearpage
+% \section{The Macros}
+%
+%    \begin{macrocode}
+\ProvidesPackage{blkarray}[2015/02/27 v0.07 Block array (dpc)]\relax
+%    \end{macrocode}
+%
+% \subsection{Some General Control Macros}
+% The macros in this section do not have the "BA" prefix, but rather the
+% "GC" prefix, other style files can repeat these definitions without
+% using up \TeX's memory.
+%
+%
+% \LaTeX\ provides "\z@", "\@ne", "\tw@", "\thr@@", but I needed some
+% more\ldots
+%    \begin{macrocode}
+\chardef\GC@four=4
+\chardef\GC@five=5
+\chardef\GC@six=6
+%    \end{macrocode}
+%
+% \subsubsection{Tests}
+%
+% Tests are like "\ifs" except that instead of the\\
+% "\if"\ldots\meta{true-text}"\else"\meta{false-text}"\fi"\\
+% notation, they have\\
+% "\test"\ldots"{"\meta{true-text}"}{"\meta{false-text}"}"\\
+% They are constructed such that they expand directly to either the
+% \meta{true-text} or \meta{false-text}, without leaving a trailing
+% "\fi".
+%
+%    \begin{macrocode}
+\def\GC@newtest#1{%
+  \@namedef{#1true}%
+    {\expandafter\let\csname test#1\endcsname\GC@true}%
+  \@namedef{#1false}%
+    {\expandafter\let\csname test#1\endcsname\GC@false}%
+  \@nameuse{#1false}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\GC@def@testfromif#1#2\fi{%
+  \def#1##1##{#2##1\expandafter\GC@true\else\expandafter\GC@false\fi}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\GC@true#1#2{#1}
+\def\GC@false#1#2{#2}
+%    \end{macrocode}
+%
+% This "\testGC@num" is not very good as it does not delimit the
+% \meta{number}s correctly.
+%    \begin{macrocode}
+\GC@def@testfromif\testGC@x\ifx\fi
+\GC@def@testfromif\testGC@num\ifnum\fi
+%    \end{macrocode}
+%
+% \subsubsection{List Macros}
+%
+% If "\X" is "abc" then "\GC@add@to@front\X{xyz}" is "xyzabc";
+%    \begin{macrocode}
+\long\def\GC@add@to@front#1#2{%
+  \def\@tempa##1{\gdef#1{#2##1}}%
+  \expandafter\@tempa\expandafter{#1}}
+%    \end{macrocode}
+%
+% and "\GC@add@to@end\X{xyz}" is "abcxyz".
+%    \begin{macrocode}
+\long\def\GC@add@to@end#1#2{%
+  \expandafter\gdef\expandafter#1\expandafter{#1#2}}
+%    \end{macrocode}
+%
+% \subsection{Allocations}
+%
+% I have given `meaningful names' to plain-\TeX's scratch registers, I
+% am not sure this was a good idea, but it should be OK as long as I
+% always access by name, and do not use, say, "\count4" as a scratch
+% register. I do not like using numbered registers in the code, and can
+% not afford to allocate registers just to get nice names, they are in
+% too short supply already!
+%
+% Only allocate another register if {\tt blockarray} is going to lose
+% control at a point where the register value needs to be saved. (eg
+% inside a "\BAnoalign" anything can happen.
+%
+% "\BAtracing" can be set to any integer, the higher the number, the
+% more gets printed.
+%    \begin{macrocode}
+%<*tracing>
+\chardef\BAtracing=0
+%</tracing>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\newcounter{BAenumi}\let\BA@row\c@BAenumi
+\countdef\BA@row@shadow=6
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\countdef\BA@ftn@shadow=0
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\newcount\BA@col
+\countdef\BA@col@shadow=2
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\newcount\BA@block@cnt
+\countdef\BA@block@cnt@shadow=4
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\countdef\BA@col@max=8
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\newbox\BA@final@box
+\chardef\BA@final@box@shadow=8
+%    \end{macrocode}
+%
+% v0.07 use newbox  not 0 to avoid amsmath.
+%    \begin{macrocode}
+\newbox\BA@first@box
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\chardef\BA@tempbox@a=2
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\chardef\BA@tempbox@b=4
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\chardef\BA@block@box=6
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\newdimen\BA@colsep
+\BA@colsep=\tabcolsep
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\newtoks\BA@ftn
+\toksdef\BA@ftnx@shadow=0
+%    \end{macrocode}
+
+% \subsection{`Local' Variables}
+%
+% Most of {\tt blockarray} happens inside a "\halign" which means that
+% the different parts have to make global assignments if they need to
+% communicate. However many of these assignments are logically local to
+% {\tt blockarray}, or a sub-environment like {\tt block}. This means
+% that I have to manage the saving and restoring of local values `by
+% hand'.
+%
+% Three different mechanisms occured to me, I have used all of them in
+% this style, mainly just to try them out!
+%
+% \begin{itemize}
+% \item `shadowing' If  "\X" is to be assigned globally, but it is to
+% be considered local to a block of code that corresponds to a \TeX\
+% group, then it may be shadowed by a local variable "\Y"\\
+% "\begingroup\Y=\X"\\
+% "\begingroup"\\
+% \meta{arbitrary code making global assignments to {\tt X}}\\
+% "\endgroup"\\
+% "\global\X=\Y\endgroup".\\
+% The inner group is needed to protect "\Y" from being changed.
+%
+% This is effectively the situation in the {\tt blockarray} environment,
+% where the outer group is provided by "\begin"\ldots"\end", and the
+% inner group is provided by an assignment to a box register.
+% \item Generating new command names, according to nesting depth.
+% Instead of directly using "\X", the variable can always be indirectly
+% accessed by "\csname\nesting X\endcsname". Here "\nesting" should
+% expand to a different sequence of tokens for each nested scope in
+% which "\X" is  used. "\nesting" might be altered by a local
+% assignment, or sometimes  need to be globally incremented at the start
+% of the scope, and globally decremented at the end.
+% \item Maintaining a stack of previous values. Corresponding to  a
+% macro, "\X", is a macro"\Xstack" which consists of a list of the
+% values of "\X" in all outer environments. When the local scope ends,
+% this stack is popped, and the top value (which was the value of "\X"
+% before the environment) is globally assigned to "\X".
+% \end{itemize}
+%
+% The first method has the advantage that the variable is normally
+% accessed within the environment, and the code to restore previous
+% values is trivial. The main memory usage is in the save-stack, \TeX's
+% normal place for saving local vaues.
+%
+% Shadowing can only be used when the environment corresonds to a \TeX\
+% group. The {\tt block} environment does not!, "\end{block}" is not in
+% the scope of any local assignments made by "\begin{block}".
+%
+% The second method, has the advantage that, once the access functions
+% are defined, it is easy to declare new local variables, however unless
+% you keep track of what has been produced, these variables will
+% continue to take up memory space, even after the environment has
+% ended. {\tt blockarray} at the moment does not do much clearing up, so
+% after a {\tt blockarray} there are typically five macros per column
+% per block (u-part, v-part, left right and `mid' delimiters) left
+% taking up space. Not to mention macros containing the texts of any
+% non-aligned entries.
+%
+%
+% An extra `"."' will locally be added to "\BA@nesting" as each {\tt
+% blockarray} is entered, this is used as described above.
+%    \begin{macrocode}
+\def\BA@nesting{}
+%    \end{macrocode}
+%
+% These two macros help in accessing macros that are `local' to the
+% current value of "\BA@nesting".
+%    \begin{macrocode}
+\def\BA@expafter#1#2{%
+  \expandafter#1\csname BA@\BA@nesting#2\endcsname}
+\def\BA@use#1{\csname BA@\BA@nesting#1\endcsname}
+%    \end{macrocode}
+%
+% These are similar, but for macros which depend on the column and block
+% involved, not just the outer {\tt blockarray} environment.
+%    \begin{macrocode}
+\def\BA@col@expafter#1#2{%
+  \expandafter#1%
+    \csname BA@\BA@nesting[\BA@use{blocktype},\the\BA@col]#2\endcsname}
+\def\BA@col@use#1{%
+  \csname BA@\BA@nesting[\BA@use{blocktype},\the\BA@col]#1\endcsname}
+%    \end{macrocode}
+%
+% The following macros manage a stack as described in the third method
+% above.
+%    \begin{macrocode}
+\def\BA@push@blocktype{%
+\edef\@tempa{{{\BA@use{blocktype}}}}%
+  \BA@expafter\GC@add@to@front{BTstack\expandafter}\@tempa}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@pop@blocktype{%
+\BA@expafter\BA@pop@{BTstack}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@pop@#1{\expandafter\BA@pop@@#1\@@}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@pop@@#1#2\@@{%
+  \BA@expafter\gdef{blocktype}{#1}%
+  \BA@expafter\gdef{BTstack}{#2}}
+%    \end{macrocode}
+%
+% \subsection{The Block Environment}
+%
+%    \begin{macrocode}
+\def\BA@beginblock#1{%
+  \noalign{%
+    \BA@push@blocktype
+    \global\advance\BA@block@cnt\@ne
+    \penalty\the\BA@block@cnt
+    \BA@expafter\xdef{blocktype\expandafter}\expandafter
+      {\the\BA@block@cnt}%
+    \penalty\@ne
+    \global\BA@col=1
+    \global\BA@expafter\def{blank@row}{\crcr}%
+    \BA@clear@entry
+    \global\let\BA@l@expr\@empty\global\let\BA@r@expr\@empty
+    \BA@colseptrue
+    \BA@parse#1\BA@parseend
+    \ifnum\BA@col@max=\BA@col\else
+       \@latexerr{wrong number of columns in block}\@ehc\fi
+    \global\BA@col\z@}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@endblock{%\crcr
+  \noalign{%
+  \BA@pop@blocktype
+  \penalty\BA@use{blocktype}%
+  \penalty\tw@}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\@namedef{BA@beginblock*}#1{%
+  \noalign{%
+    \BA@push@blocktype
+    \global\advance\BA@block@cnt\@ne
+    \BA@expafter\xdef{blocktype\expandafter}\expandafter
+      {\the\BA@block@cnt}%
+    \global\BA@col=\@ne
+    \global\BA@expafter\def{blank@row}{\crcr}%
+    \BA@stringafter\let\Left\BA@left@warn
+    \BA@stringafter\let\Right\BA@right@warn
+    \BA@clear@entry
+    \global\let\BA@l@expr\@empty\global\let\BA@r@expr\@empty
+    \BA@colseptrue
+    \BA@parse#1\BA@parseend
+    \ifnum\BA@col@max=\BA@col\else
+       \@latexerr{wrong number of columns in block*}\@ehc\fi
+    \global\BA@col\z@}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@left@warn#1#2{%
+  \@warning{Left delimiter, \string#2, ignored}\BA@parse}
+\def\BA@right@warn#1#2{%
+  \@warning{Right delimiter, \string#1, ignored}\BA@parse}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\@namedef{BA@endblock*}{%\crcr
+  \noalign{%
+  \BA@pop@blocktype}}
+%    \end{macrocode}
+%
+% \subsection{Multicolumn}
+%
+% First we have the "\multicolumn" command to be used as in original
+% \LaTeX.
+%
+%    \begin{macrocode}
+\def\BAmulticolumn#1#2#3{%
+  \multispan{#1}%
+  \global\advance\BA@col#1\relax
+  \edef\BA@nesting{\BA@nesting,}%
+  \BA@expafter\def{blocktype}{0}%
+  {\BA@defcolumntype{&}##1\BA@parseend{%
+     \@latexerr{\string& in multicolumn!}\@ehc\BA@parse\BA@parseend}%
+  \global\BA@expafter\def{blank@row}{\crcr}%
+  \BA@clear@entry
+  \global\let\BA@l@expr\@empty\global\let\BA@r@expr\@empty
+  \BA@colseptrue
+  \BA@parse#2\BA@parseend}%
+  \BA@strut\BA@col@use{u}\ignorespaces#3\BA@vpart}
+%    \end{macrocode}
+%
+% Now something more interesting, a "\BAmulticolumn" column
+% specification!
+%
+%    \begin{macrocode}
+\def\BA@make@mc#1{%
+  \count@#1\relax
+  \BA@make@mcX
+  \edef\BA@mc@hash{%
+    \noexpand\BA@parse
+     >{\BA@mc@spans}\noexpand\BA@MC@restore@hash
+     \BA@mc@amps\noexpand\BA@MC@switch@amp}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@make@mcX{%
+  \ifnum\count@=\@ne
+    \def\BA@mc@spans{\null}%
+    \let\BA@mc@amps\@empty
+  \else
+   \advance\count@\m@ne
+    \BA@make@mcX
+    \GC@add@to@end\BA@mc@spans{\span}%
+    \GC@add@to@end\BA@mc@amps{&@{}}%
+  \fi}
+%    \end{macrocode}
+%
+% \subsection{\tt\bslash BAmultirow}
+%
+% First as a command.
+%
+%    \begin{macrocode}
+\long\def\BAmultirow#1{\kern#1\relax
+  \global\BA@quickfalse
+  \BA@col@expafter\gdef{mid}}
+%    \end{macrocode}
+%
+% Then as a column specification. (The actual "\BAnewcolumn" comes
+% later)
+%
+%    \begin{macrocode}
+\def\BA@mrow@bslash#1{%
+  \kern#1\relax
+  \global\BA@quickfalse
+  \iffalse{\else\let\\\cr\fi\iffalse}\fi
+  \BA@mrow}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\long\def\BA@mrow#1\BA@vpart{%
+  \BA@col@expafter\GC@add@to@end{mid}{\endgraf#1}
+  \BA@vpart}
+%    \end{macrocode}
+%
+% \subsection{\tt\bslash BAnoalign}
+%
+%    \begin{macrocode}
+\def\BAnoalign{%\crcr
+  \noalign{\ifnum0=`}\fi
+     \global\BA@quickfalse
+     \penalty\the\BA@row
+  \@ifstar
+      {\penalty\GC@four\BA@noalign}%
+      {\penalty\BA@use{blocktype}\penalty\thr@@\BA@noalign}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\long\def\BA@noalign#1{%
+  \long\BA@expafter\gdef{noalign\the\BA@row}{#1}%
+  \ifnum0=`{\fi}}
+%    \end{macrocode}
+%
+% \subsection{\tt\bslash\bslash}
+%
+% The following code is taken directly from "array.sty", apart from some
+% name changes. It is very similar to the version in {\tt latex.tex}.
+% Making "\\" into a macro causes problems when you want the entry to be
+% taken as a macro argument. One possibility is to "\let" "\\" be
+% "\span", and then have the \meta{u-part} of a final column parse the
+% optional argument. There is still a problem with "\end{...}". Note
+% that at the moment this style assumes that "\\" is used at the end of
+% all lines except the last, even before "\begin{block}" or
+% "\end{block}", this allows spacing to be specified, and also
+% approximates to the truth about what is actually happening. The idea
+% of making it easier to allow entries to be taken as arguments may be a
+% non-starter if "&" is allowed to become a `short-ref' (ie "\active")
+% character.
+%
+%    \begin{macrocode}
+\def\BA@cr{{\ifnum 0=`}\fi
+  \@ifstar \BA@xcr \BA@xcr}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@xcr{\@ifnextchar [%
+  \BA@argcr {\ifnum 0=`{\fi}\cr}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@argcr[#1]{\ifnum0=`{\fi}\ifdim #1>\z@
+  \BA@xargcr{#1}\else \BA@yargcr{#1}\fi}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@xargcr#1{\unskip
+  \@tempdima #1\advance\@tempdima \dp\@arstrutbox
+  \vrule \@depth\@tempdima \@width\z@ \cr}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@yargcr#1{\cr\noalign{%
+     \vskip #1}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\newdimen\BAextrarowheight
+\newdimen\BAextraheightafterhline
+\newdimen\BAarrayrulewidth
+   \BAarrayrulewidth\arrayrulewidth
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\newdimen\BAdoublerulesep
+   \BAdoublerulesep\doublerulesep
+%    \end{macrocode}
+%
+% The B form of the strut is an extra high strut to use after a
+% horizontal rule.
+%    \begin{macrocode}
+\def\BA@strut{\unhcopy\@arstrutbox}
+\let\BA@strutA\BA@strut
+\def\BA@strutB{\dimen@\ht\@arstrutbox
+  \advance\dimen@\BAextraheightafterhline
+  \vrule \@height\dimen@ \@depth \dp\@arstrutbox \@width\z@
+  \global\let\BA@strut\BA@strutA}
+%    \end{macrocode}
+%
+% \subsection{Begin and End}
+%
+% "\begin{block}" is supposed to expand to "\noalign{...", but the code
+% for "\begin" would place non-expandable tokens before the "\noalign".
+% Within the {\tt blockarray} environment, redefine "\begin" so that if
+% its argument corresponds to a command "\BA@begin"\meta{argument}, then
+% directly directly expand that command, otherwise do a normal "\begin".
+% A matching change is made to "\end".
+%    \begin{macrocode}
+\let\BA@@begin\begin
+\let\BA@@end\end
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@begin#1{%
+  \expandafter\testGC@x\csname BA@begin#1\endcsname\relax
+    {\BA@@begin{#1}}%
+    {\csname BA@begin#1\endcsname}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@end#1{%
+  \expandafter\testGC@x\csname BA@end#1\endcsname\relax
+    {\BA@@end{#1}}%
+    {\csname BA@end#1\endcsname}}
+%    \end{macrocode}
+%
+% \subsection{The {\tt blockarray} Environment}
+%
+%    \begin{macrocode}
+\def\blockarray{\relax
+  \@ifnextchar[{\BA@blockarray}{\BA@blockarray[c]}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@blockarray[#1]#2{%
+  \expandafter\let\expandafter\BA@finalposition
+    \csname BA@position@#1\endcsname
+  \let\begin\BA@begin
+  \let\end\BA@end
+  \ifmmode
+    \def\BA@bdollar{$}\let\BA@edollar\BA@bdollar
+  \else
+    \setbox\z@\hbox{$$}%set up math for NFSS (2014/10/16)
+    \def\BA@bdollar{\bgroup}\def\BA@edollar{\egroup}%
+    \let\BA@bdollar\bgroup\let\BA@edollar\egroup
+  \fi
+  \let\\\BA@cr
+%    \end{macrocode}
+% Currently I use "\everycr" this means that every macro that uses
+% "\halign" that might be used inside a {\tt blockarray} must locally
+% clear "\everycr". The version of {\tt array} in {\tt array.sty} does
+% this, but not the one in {\tt latex.tex}.
+%    \begin{macrocode}
+  \everycr{\noalign{%
+     \global\advance\BA@row\@ne
+     \global\BA@col\z@}}%
+%    \end{macrocode}
+% The "\extrarowheight" code from {\tt array.sty}.
+%    \begin{macrocode}
+  \@tempdima \ht \strutbox
+  \advance \@tempdima by\BAextrarowheight
+  \setbox\@arstrutbox \hbox{\vrule
+             \@height \arraystretch \@tempdima
+             \@depth \arraystretch \dp \strutbox
+             \@width \z@}%
+%    \end{macrocode}
+% As explained above various registers which are `local' to {\tt
+% blockarray} are always accessed globally, and so must be shadowed by
+% local copies, so that the values can be restored at the end.
+%    \begin{macrocode}
+  \BA@col@shadow=\BA@col
+    \global\BA@col=\@ne
+  \BA@block@cnt@shadow=\BA@block@cnt
+    \global\BA@block@cnt\@M
+  \BA@row@shadow\BA@row
+    \global\BA@row\z@
+  \setbox\BA@final@box@shadow=\box\BA@final@box
+    \global\setbox\BA@final@box=\box\voidb@x
+  \let\BA@delrow@shadow=\BA@delrow
+  \let\testBA@quick@shadow\testBA@quick
+    \global\BA@quicktrue
+%    \end{macrocode}
+% If we are using tablenotes, shadow the footnote counter (or possibly
+% mpfootnote), and set up the print style for the table notes.
+%    \begin{macrocode}
+  \testBAtablenotes
+    {\edef\BA@mpftn{\csname c@\@mpfn\endcsname}%
+     \@namedef{the\@mpfn}{\BA@fnsymbol{\@nameuse{c@\@mpfn}}}%
+     \BA@ftn@shadow=\BA@mpftn\global\BA@mpftn\z@
+     \BA@ftnx@shadow=\expandafter{\the\BA@ftn}\global\BA@ftn{}%
+      }{}%
+%    \end{macrocode}
+% Locally increase "\BA@nesting" so that macros accessed by `the second
+% method' will be local to this environment.
+%    \begin{macrocode}
+  \edef\BA@nesting{\BA@nesting.}%
+%    \end{macrocode}
+% Now start up the code for this block
+%    \begin{macrocode}
+  \BA@expafter\xdef{blocktype}{10000}%
+  \BA@expafter\xdef{BTstack}{\relax}%
+  \global\BA@expafter\def{blank@row}{\crcr}%
+  \setbox\BA@first@box=\vbox{\ifnum0=`}\fi
+    \let\@footnotetext\BA@ftntext\let\@xfootnotenext\BA@xftntext
+    \lineskip\z@\baselineskip\z@
+    \BA@clear@entry
+    \global\let\BA@l@expr\BA@bdollar\global\let\BA@r@expr\BA@edollar
+    \global\let\BA@l@expr\@empty\global\let\BA@r@expr\@empty
+    \BA@colseptrue
+    \BA@parse#2\BA@parseend
+    \BA@col@max=\BA@col
+%    \end{macrocode}
+% There had to be a "\halign" somewhere, and here it is!
+%
+% Currently I am using a `repeating preamble' because it was easier, but
+% I think that I should modify the columntypes for {\tt blockarray} (not
+% {\tt block}) so that they construct a preamble with the right number
+% of columns. this would give better error checking, and would give the
+% possibility of modifying the tabskip glue.
+%    \begin{macrocode}
+    \tabskip\z@
+    \halign\bgroup\BA@strut%\global\BA@col=\z@
+       \BA@upart##\BA@vpart&&\BA@upart##\BA@vpart\cr
+       \noalign{\penalty\GC@five}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@upart{\global\advance\BA@col\@ne\BA@col@use{u}\ignorespaces}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@vpart{\unskip\BA@col@use{v}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@clear@entry{%
+  \global\BA@col@expafter\let{u}\@empty
+  \global\BA@col@expafter\let{v}\@empty
+  \global\BA@col@expafter\let{left}\relax
+  \global\BA@col@expafter\let{mid}\@empty
+  \global\BA@col@expafter\let{right}\relax
+  \BA@uparttrue}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\let\BA@fnsymbol=\@fnsymbol
+%    \end{macrocode}
+%
+% The code to place the footnote texts at the foot of the table, each
+% footnote starting on a new line. This will only be activated if
+% "\BAtablenotestrue".
+%    \begin{macrocode}
+\def\BA@expft[#1]#2{%
+  \noindent\strut\ifodd0#11{%
+  \edef\@thefnmark
+     {\BA@fnsymbol{#1}}\@makefnmark}\else{#1}\fi\ #2\unskip\strut\par}
+%    \end{macrocode}
+%
+% After a "\BAparfootnotes" declaration, the table notes will be set in
+% a single paragraph, with a good chance of line breaks occuring at the
+% start of a footnote.
+%    \begin{macrocode}
+\def\BAparfootnotes{%
+  \def\BA@expft[##1]##2{%
+   \noindent\strut\ifodd0##11{%
+     \edef\@thefnmark{\BA@fnsymbol{##1}}\@makefnmark}\else{##1~}\fi
+   ##2\unskip\strut\nobreak
+  \hskip \z@ plus 3em \penalty\z@\hskip 2em plus -2.5em minus .5em}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\endblockarray{%
+%    \end{macrocode}
+% At this point, if no delimiters, "\BAnoalign", or "\BAmultirow" have
+% been used, just finish here, this makes {\tt blockarray} was just
+% about as efficient as {\tt array} If no fancy tricks have been used.
+%    \begin{macrocode}
+  \testBA@quick\BA@quick@end\BA@work@back@up
+%    \end{macrocode}
+% Now we restore the values  that have been `shadowed' by versions that
+% are local to this environment.
+%    \begin{macrocode}
+  \global\BA@block@cnt=\BA@block@cnt@shadow
+  \global\BA@col=\BA@col@shadow
+  \global\BA@row=\BA@row@shadow
+  \global\setbox\BA@final@box=\box\BA@final@box@shadow
+  \global\let\BA@delrow=\BA@delrow@shadow
+  \global\let\BA@delrow=\BA@delrow@shadow
+  \global\let\testBA@quick\testBA@quick@shadow
+%    \end{macrocode}
+% If tablenotes are being used, reset the shadowed list of footnotes.
+% Otherwise execute the list now, to pass the footnotes on to the outer
+% environment, or the current page.
+%    \begin{macrocode}
+  \testBAtablenotes
+    {\global\BA@mpftn=\BA@ftn@shadow
+     \global\BA@ftn=\expandafter{\the\BA@ftnx@shadow}}
+    {\global\BA@ftn\expandafter{\expandafter}\the\BA@ftn}}
+%    \end{macrocode}
+%
+% Here is the `quick ending': just position the box as specified by
+% "[tcb]", possibly adding footnotes.
+%    \begin{macrocode}
+\def\BA@quick@end{%
+  \crcr
+  \egroup% end of halign
+  \ifnum0=`{\fi}% end of \BA@first@box
+%<*tracing>
+     \ifnum\BAtracing>\z@\typeout{Quick blockarray ends \on@line}\fi
+%</tracing>
+   \leavevmode\BA@finalposition\BA@first@box}
+%    \end{macrocode}
+%
+% If any delimiters or noaligns have been used, we must take apart the
+% table built in "\BA@first@box", and reassemble it. This is done by
+% removing the rows one by one, starting with the last row, using
+% "\lastbox".
+%    \begin{macrocode}
+\def\BA@work@back@up{%
+  \BA@use{blank@row}%
+  \egroup% end of halign
+  \setbox\@tempboxa=\lastbox
+  \unskip
+  \BA@getwidths
+%<*tracing>
+     \ifnum\BAtracing>\z@\typeout{Full blockarray ends \on@line}\fi
+%</tracing>
+%<*tracing>
+   \ifnum\BAtracing>\thr@@
+     \egroup\showbox\BA@first@box
+     \setbox\BA@first@box=\vbox\bgroup\unvbox\BA@first@box
+   \fi
+%</tracing>
+  \setbox\BA@block@box=\box\voidb@x
+  \BA@check@pen
+  \ifnum0=`{\fi}% end of \BA@first@box
+%<*check>
+  \dimen@=\ht\BA@first@box\advance\dimen@\dp\BA@first@box
+  \ifdim\dimen@>\z@\showthe\dimen@\fi
+%</check>
+     \leavevmode\BA@finalposition\BA@final@box}
+%    \end{macrocode}
+%
+% These macros position the final box, they are just first attempts. In
+% particular "[t]" does not work properly because the guard penalty used
+% to terminate the main loop means that "\BA@first@box" always has zero
+% height. Also if the box has been taken apart, "[t]" and "[b]" will
+% cause the position to be based on the {\em centre\/} of the
+% corresponding block.
+%
+% If tablenotes are being used, package the table in a box with the
+% notes.
+%    \begin{macrocode}
+\newdimen\BAfootskip
+\BAfootskip=1em
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@position@c#1{\hbox{%
+     \testBAtablenotes
+      {\let\footnotetext\BA@expft
+       \hsize\wd#1\@parboxrestore\footnotesize}%
+      {}%
+     $\vcenter{%
+      \unvbox#1%
+      \testBAtablenotes
+        {\vskip\BAfootskip
+         \the\BA@ftn}{}%
+      }$}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@position@t#1{\vtop{%
+     \testBAtablenotes
+      {\let\footnotetext\BA@expft
+       \hsize\wd#1\@parboxrestore\footnotesize}%
+      {}%
+      \unvbox#1%
+      \testBAtablenotes
+        {\vskip\BAfootskip
+         \the\BA@ftn}{}}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@position@b#1{%
+    \testBAtablenotes
+      {\vbox{%
+        \let\footnotetext\BA@expft
+        \hsize\wd#1\@parboxrestore\footnotesize
+        \unvbox#1%
+        \vskip\BAfootskip
+        \the\BA@ftn}}%
+      {\box#1}}
+%    \end{macrocode}
+%
+%
+% \subsection{Fitting the Parts Together}
+%
+% Get the widths of each column. It also faithfully copies the tabskip
+% glue, even though currently this is always 0pt. The width of the
+% column is put into "\BA@delrow" as the argument to the (unexpanded)
+% call to "\BA@lr".
+%    \begin{macrocode}
+\def\BA@getwidths{%
+  \setbox\@tempboxa=\hbox{\unhbox\@tempboxa
+    \xdef\BA@delrow{\hskip\the\lastskip}\unskip
+    \let\BA@lr\relax
+    \loop
+    \setbox\BA@tempbox@a=\lastbox
+    \skip\z@=\lastskip\unskip
+    \ifhbox\BA@tempbox@a
+    \xdef\BA@delrow{%
+      \hskip\the\skip\z@\BA@lr{\the\wd\BA@tempbox@a}\BA@delrow}%
+    \repeat}}
+%    \end{macrocode}
+%
+% The main mechanism by which {\tt blkarray} leaves information to be
+% used `on the way back' is to leave groups of penalties in the main
+% box.
+% The last penalty in each group (the first to be seen on the way back)
+% is a code penalty, it has the following meanings:\\
+% "\penalty 1" --- "\begin{block}"\\
+% "\penalty 2" --- "\end{block}"\\
+% "\penalty 3" --- "\BAnoalign"\\
+% "\penalty 4" --- "\BAnoalign*"\\
+% "\penalty 5" --- "\begin{blockarray}"\\
+% Note that the {\tt block*} environment does not produce any penalties,
+% this environment is just as efficient as "\multicolumn", and does not
+% require the second phase, coming back via "\lastbox".
+%
+% Above the code penalty may be other penalties, depending on the code,
+% typically these have the values of the blocktype for the block, or the
+% row number.
+%    \begin{macrocode}
+\def\BA@check@pen{%
+  \count@=\lastpenalty\unpenalty
+  \ifcase\count@
+%    \end{macrocode}
+% Grumble Grumble. "\lastpenalty" should be {\tt void} if the previous
+% thing was not a penalty, and there should be an "\ifvoid\lastpenalty"
+% or something equivalent to test for this. If the user manages to get a
+% "\penalty0" into the main box, it will just have to be discarded.
+% Actually that is not disastrous, but if a rule, mark, special, insert
+% or write gets into that box {\tt blockarray} will go into an infinite
+% loop. Every class of \TeX\ object should have a "\last"\ldots\
+% so that boxes may be taken apart and reconstructed by special styles
+% like this. \TeX\ of course is frozen, so these missing features will
+% never be added (while the system is called \TeX).
+%
+%    \begin{macrocode}
+%<*tracing>
+     \ifnum\BAtracing>\tw@\typeout{0-???}\fi
+%</tracing>
+     \BA@get@row
+  \or
+%<*tracing>
+     \ifnum\BAtracing>\tw@\typeout{1-block}\fi
+%</tracing>
+     \BA@expafter\xdef{blocktype}{\the\lastpenalty}\unpenalty
+     \ifnum\lastpenalty=\tw@
+%<*tracing>
+       \ifnum\BAtracing>\tw@\typeout{discarding 2-endblock}\fi
+%</tracing>
+       \unpenalty\unpenalty\fi
+     \BA@place
+  \or
+%<*tracing>
+     \ifnum\BAtracing>\tw@\typeout{2-endblock}\fi
+%</tracing>
+     \BA@expafter\xdef{blocktype}{\the\lastpenalty}\unpenalty
+     \BA@place
+  \or
+%<*tracing>
+     \ifnum\BAtracing>\tw@\typeout{3-BAnoalign}\fi
+%</tracing>
+     \BA@expafter\xdef{blocktype}{\the\lastpenalty}\unpenalty
+     \BA@place
+     \count@=\lastpenalty\unpenalty
+     \global\setbox\BA@final@box=\vbox{%
+       \hsize=\wd\BA@final@box\@parboxrestore
+       \vrule \@height \ht\@arstrutbox \@width \z@
+       \BA@use{noalign\the\count@}
+       \vrule \@width \z@ \@depth \dp \@arstrutbox
+       \endgraf\unvbox\BA@final@box}%
+  \or
+%<*tracing>
+     \ifnum\BAtracing>\tw@\typeout{4-BAnoalign*}\fi
+%</tracing>
+     \count@=\lastpenalty\unpenalty
+     \setbox\BA@block@box=\vbox{%
+       \hsize=\wd\BA@final@box \@parboxrestore
+       \vrule \@height \ht\@arstrutbox \@width \z@
+       \BA@use{noalign\the\count@}
+       \vrule \@width \z@ \@depth \dp \@arstrutbox
+       \endgraf\unvbox\BA@block@box}%
+  \or
+%<*tracing>
+     \ifnum\BAtracing>\tw@\typeout{5-blockarray}\fi
+%</tracing>
+     \BA@expafter\xdef{blocktype}{10000}
+     \BA@place
+     \let\BA@check@pen\relax
+  \fi
+  \BA@check@pen}
+%    \end{macrocode}
+%
+% Move a row of the table from the "\BA@first@box" into the block that
+% is being constructed in "\BA@block@box".
+%    \begin{macrocode}
+\def\BA@get@row{%
+  \skip@=\lastskip\unskip
+  \advance\skip@\lastskip\unskip
+  \setbox\@tempboxa=\lastbox
+  \setbox\BA@block@box=\vbox{%
+     \box\@tempboxa
+     \vskip\skip@
+     \unvbox\BA@block@box}}
+%    \end{macrocode}
+%
+% Place the block that has been constructed in "\BA@block@box", together
+% with any delimiters, or spanning entries which have been assembled
+% into "\BA@delrow", into the final table, which is being constructed in
+% "\BA@final@box".
+%    \begin{macrocode}
+\def\BA@place{%
+  \global\setbox\BA@final@box=\vbox{\hbox{%
+    \m@th\nulldelimiterspace=\z@
+    \dimen\z@=\ht\BA@block@box
+    \advance\dimen\z@ by \dp\BA@block@box
+    \divide\dimen\z@\tw@
+    \dimen\tw@=\dimen\z@
+    \advance\dimen\z@ by\fontdimen22 \textfont\tw@
+    \advance\dimen2 by-\fontdimen22 \textfont\tw@
+    \global\BA@col=\z@
+    \delimitershortfall=10pt
+    \delimiterfactor=800
+    \BA@delrow
+    \kern-\wd\BA@block@box
+    \ht\BA@block@box=\dimen\z@ \dp\BA@block@box=\dimen\tw@
+    \box\BA@block@box}
+  \unvbox\BA@final@box}}
+%    \end{macrocode}
+%
+%
+% Place the delimiters or spanning entries in position for one column of
+% the current block.
+%    \begin{macrocode}
+\def\BA@lr#1{%
+ \global\advance\BA@col\@ne\relax
+ \BA@col@use{left}%
+ \BA@col@expafter\ifx{mid}\@empty
+   \kern#1
+ \else
+   \hbox to #1{%
+      \setbox\BA@tempbox@a
+        \hbox{\let\BA@mrow@bslash\@gobble\BA@col@use{u}\BA@edollar}%
+      \setbox\BA@tempbox@b
+        \hbox{\BA@bdollar\BA@col@use{v}}%
+     \kern\wd\BA@tempbox@a
+     $\vcenter{%
+      \hsize=#1
+      \advance\hsize-\wd\BA@tempbox@a
+      \advance\hsize-\wd\BA@tempbox@b
+      \@parboxrestore\BA@col@use{mid}}$%
+     \kern\wd\BA@tempbox@b}%
+ \fi
+ \BA@col@use{right}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@leftdel#1#2#3{%
+  \llap{%
+    {#1}$\left#2\vrule height \dimen\z@ width\z@ \right.$\kern-#3}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@rightdel#1#2#3{%
+  \rlap{%
+    \kern-#3$\left.\vrule height \dimen\z@ width\z@ \right#1${#2}}}%
+%    \end{macrocode}
+%
+% \subsection{Parsing the Column Specifications}
+%
+% A token "x" in the column specification, is interpreted by "\BA@parse"
+% as "\BA@<x>". This command is then expanded, which may take further
+% tokens as arguments.
+% The expansion of "\BA@<x>" is supposed to end with a call to
+% "\BA@parse" which will convert the token following any arguments to a
+% control sequence name. The process is terminated by the token
+% "\BA@parseend" as the coresponding command "\BA@<\BA@parseend>" does
+% some `finishing off', but does not call "\BA@parse".
+%
+% There are two commands to help in defining column types.\\
+% "\BA@defcolumntype" This takes its parameter specification in the
+% primitive "\def" syntax, and allows the replacement text to be
+% anything.\\
+% "\BAnewcolumntype" This takes its parameter specification in \LaTeX's
+% "\newcommand" syntax, and applies "\BA@parse" to the {\em front\/} of
+% the replacement text. This is intended for users to define their own
+% column types in terms of primitive column types, rather than in terms
+% of arbitrary \TeX\ expressions.
+%
+% The preamble argument build up various macros as as follows:
+%
+% Each entry in the "\halign" preamble is of the form\\
+% "\BA@upart#\BA@vpart"\\
+% "\BA@upart" increments "\BA@col", and then expands
+% "\BA@col@use{u}", similarly "\BA@vpart" expands
+% "\BA@col@use{v}".
+%
+% "\BA@col@use{u}" is a macro considered local to the current block
+% and column, it is always accessed via "\BA@col@use" or
+% "\BA@col@expafter". So the preamble entries must result in
+% "\BA@col@use{u}" and "\BA@col@use{v}" being defined to enter
+% any text specified in "@"-expressions, the inter-column space (in the
+% \LaTeX\ tradition, not "\tabskip"), and any declarations in ">" and
+% "<" expressions. Delimiters are not added to these macros as they
+% correspond to the whole block, they are left in the macros
+% "\BA@col@use{left}" and "\BA@col@use{right}" spanning entries from
+% "\BAmultirow" are considered like delimiters, and left in
+% "\BA@col@use{mid}".
+%
+% If the test "\testBA@upart" is true, then the \meta{u-part} is being
+% built. This consists of three different sections.\\
+% 1) The left inter-column text, declared in "!"- and "@"-expressions\\
+% 2) The left inter-column skip.\\
+% 3) Any declarations specified in ">" expressions.
+%
+% Suppose "X" is a column type, which may itself be defined in terms of
+% other column types, then the (equivalent) specifications:\\
+% "@{aaa}>{\foo}X" and ">{\foo}@{aaa}X"\\
+% must result in "aaa", surrounded by
+% {\tt\protect\bslash bgroup}\ldots{\tt\protect\bslash egroup} or
+% {\tt\$}\ldots{\tt\$},  being prepended to the
+% {\em front\/} of the u-part, and "\foo" being appended to the end, so
+% that it is the innermost declaration to be applied to the entries in
+% that column.
+%
+% In order to achieve this, ">" expressions are directly added to the
+% u-part, using "\GC@add@to@front", "@"- and "!"- expressions (and rules
+% from "|") are added to a scratch macro, "\BA@l@expr", using
+% "\GC@add@to@end".
+%
+% When the next "#" column specifier is reached, the "\BA@l@expr" is
+% added to the front of the u-part, It is separated from the
+% ">"-expressions by a \meta{hskip} unless an "@"-expression has
+% occured, either while building the current u-part, or the previous
+% v-part.
+%
+%  Building the v-part is similar.
+%
+% This procedure has certain consequences,
+% \begin{itemize}
+%  \item "@{a}@{b}" is equivalent to "@{ab}", or more correctly
+%  "@{{a}{b}}".
+%  \item ">{\a}>{\b}" is equivalent to ">{\b\a}".
+% \item If any "@"-expression occurs between two columns, all
+% "!"-expressions between those columns will be treated identically to
+% "@"-expressions. This differs from {\tt array.sty} where two
+% "!"-expressions are separated by the same skip as the rules specified
+%   by "||".
+%  \item If any rule "|" occurs, then a following rule will be preceded
+%  by the doubleruleskip, unless a "@" or "!"-expression comes between
+%  them. In particular "|&|" specifies a double rule, which looks the
+%  same as "||", but "\multicolumn" commands can be used to remove one
+%  or other of the rules for certain entries.
+% \end{itemize}
+%
+% Create a macro name from a column specifier.
+%    \begin{macrocode}
+\def\BA@stringafter#1#2{\expandafter#1\csname BA@<\string#2>\endcsname}
+%    \end{macrocode}
+%
+% Execute the specifier, or discard an unknown one, and try the next
+% token.
+%    \begin{macrocode}
+\def\BA@parse#1{%
+  \BA@stringafter\testGC@x{#1}\relax
+    {\@latexerr {Unknown column type, \string#1}\@ehc\BA@parse}%
+    {\csname BA@<\string#1>\endcsname}}
+%    \end{macrocode}
+%
+% "\def" for column types.
+%    \begin{macrocode}
+\def\BA@defcolumntype#1{%
+  \BA@stringafter\def{#1}}
+%    \end{macrocode}
+%
+% "\newcommand" for column types.\footnote{Currently does not check that
+% the type is new.}
+%    \begin{macrocode}
+\def\BAnewcolumntype{\@ifnextchar[{\BA@nct}{\BA@nct[0]}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@nct[#1]#2#3{%
+  \BA@stringafter\@reargdef{#2}[#1]{\BA@parse#3}}
+%    \end{macrocode}
+%
+% These "\if"s will be true if their associated skips are to be added in
+% the current column.
+%    \begin{macrocode}
+\newif\ifBA@colsep
+\newif\ifBA@rulesep
+%    \end{macrocode}
+%
+% This is true if we do not need to come back up the array.
+%    \begin{macrocode}
+\GC@newtest{BA@quick}
+%    \end{macrocode}
+%
+
+% This will be true if building the \meta{u-part}, and false if building
+% the \meta{v-part}.
+%    \begin{macrocode}
+\GC@newtest{BA@upart}
+%    \end{macrocode}
+%
+%
+% \subsection{`Internal' Column-Type Definitions}
+%
+% ">" expressions:\\
+%  If we are building the v-part, add a "&", and try
+% again, so that "c<{\a}>{\b}c" is equivalent to "c<{\a}&>{\b}c".\\
+% Otherwise add the expression to the front of the u-part, i.e., the
+% list being built in "\BA@col@use{u}". Note that no grouping is added
+% so that the scope of any declaration includes the column entry.
+%    \begin{macrocode}
+\BA@defcolumntype{>}#1{%
+  \testBA@upart
+   {\BA@col@expafter\GC@add@to@front{u}{#1}%
+    \BA@parse}%
+   {\BA@parse &>{#1}}}
+%    \end{macrocode}
+%
+% Left delimiters:\\
+% Again add a "&" if required, otherwise just save the delimiter and
+% label as the first two arguments of "\BA@left@del" in the macro
+% "\BA@col@use{left}".
+%    \begin{macrocode}
+\BA@defcolumntype{\Left}#1#2{%
+  \testBA@upart
+   {\global\BA@quickfalse
+    \BA@col@expafter\gdef{left}{\BA@leftdel{#1}{#2}}\BA@parse}%
+   {\BA@parse &\Left{#1}{#2}}}
+%    \end{macrocode}
+%
+% Right delimiters: As for Left.
+%    \begin{macrocode}
+\BA@defcolumntype{\Right}#1#2{%
+  \testBA@upart
+   {\BA@parse ##\Right{#1}{#2}}
+   {\global\BA@quickfalse
+    \BA@col@expafter\gdef{right}{\BA@rightdel{#1}{#2}}\BA@parse}}%
+%    \end{macrocode}
+%
+% "&" The end of each column specification is terminated by "&", either
+% by the user explicitly entering "&", or one being added by one of the
+% other rewrites.\\
+% If we are still in the u-part, finish it off with "#".\\
+% Otherwise add another column to the blank row, advance the column
+% counter by one. Finally reset the variables
+% $"\BA@use{u"|"v"|"left"|"mid"|"right}"$
+%    \begin{macrocode}
+\BA@defcolumntype{&}{%
+  \testBA@upart
+   {\BA@parse ##&}%
+   {%
+    \BA@expafter\xdef{blank@row}{\BA@use{blank@row}\omit&}%
+    \global\advance\BA@col\@ne
+    \BA@clear@entry
+    \BA@parse}}
+%    \end{macrocode}
+%
+% "#" Add a "&" if required.\\
+% Otherwise make the u-part of the current column, and the v-part of the
+% previous one.
+%
+%    \begin{macrocode}
+\BA@defcolumntype{#}{%
+  \testBA@upart
+   {%
+%    \end{macrocode}
+% Add the intercolumn skips unless a "@" expression has occured since
+% the last "#" entry.
+%    \begin{macrocode}
+    \ifBA@colsep
+       \GC@add@to@front\BA@r@expr{\BA@edollar\hskip\BA@colsep}%
+       \GC@add@to@end\BA@l@expr{\hskip\BA@colsep\BA@bdollar}%
+    \else
+       \GC@add@to@front\BA@r@expr{\BA@edollar}%
+       \GC@add@to@end\BA@l@expr{\BA@bdollar}%
+    \fi
+%    \end{macrocode}
+% Go back to the previous column. Add "\BA@r@expr" to the end of
+% "\BA@col@use{v}".
+%    \begin{macrocode}
+    \global\advance\BA@col\m@ne
+    \BA@col@expafter\GC@add@to@end{v\expandafter}\expandafter
+           {\BA@r@expr}%
+%    \end{macrocode}
+% Add the total width of any "@" expressions as the third argument in
+% the right delimiter macro, this will be used to move the delimiters
+% past any inter-column material.
+%    \begin{macrocode}
+    \BA@add@rskip
+%    \end{macrocode}
+% Repeat for the u-part, and left delimiter of the current column.
+%    \begin{macrocode}
+    \global\advance\BA@col\@ne
+    \BA@col@expafter\GC@add@to@front{u\expandafter}\expandafter
+           {\BA@l@expr}%
+     \BA@add@lskip
+%    \end{macrocode}
+% Clear these scratch macros ready for the next column.
+%    \begin{macrocode}
+    \global\let\BA@l@expr\@empty\global\let\BA@r@expr\@empty
+%    \end{macrocode}
+% Reset these tests and ifs, ready for the next inter-column material.
+%    \begin{macrocode}
+    \BA@upartfalse
+    \BA@rulesepfalse
+    \BA@colseptrue
+%    \end{macrocode}
+% Finally look at the next specifier.
+%    \begin{macrocode}
+    \BA@parse}%
+   {\BA@parse &##}}
+%    \end{macrocode}
+%
+% "<" Just like ">".
+%    \begin{macrocode}
+\BA@defcolumntype{<}#1{%
+  \testBA@upart
+   {\BA@parse ##<{#1}}%
+   {\BA@col@expafter\GC@add@to@front{v}{#1}\BA@parse}}
+%    \end{macrocode}
+%
+% "BA" version of "\vline".
+%    \begin{macrocode}
+\def\BA@vline{\vrule \@width \BAarrayrulewidth}
+%    \end{macrocode}
+%
+% "|" like "!", except that a "\hskip\BAdoublerulesep" is added for
+% consecutive pairs.
+%    \begin{macrocode}
+\BA@defcolumntype{|}{%
+  \testBA@upart
+   {\ifBA@rulesep
+      \GC@add@to@end\BA@l@expr{\hskip\BAdoublerulesep\BA@vline}%
+    \else
+      \GC@add@to@end\BA@l@expr{\BA@vline}%
+    \fi}%
+   {\ifBA@rulesep
+      \GC@add@to@end\BA@r@expr{\hskip\BAdoublerulesep\BA@vline}%
+    \else
+      \GC@add@to@end\BA@r@expr{\BA@vline}%
+    \fi}%
+  \BA@ruleseptrue
+  \BA@parse}
+%    \end{macrocode}
+%
+% "@" identical to "!", but set "\BA@colsepfalse".
+%    \begin{macrocode}
+\BA@defcolumntype{@}#1{%
+  \testBA@upart
+   {\GC@add@to@end\BA@l@expr{\BA@bdollar#1\BA@edollar}}%
+   {\GC@add@to@end\BA@r@expr{\BA@bdollar#1\BA@edollar}}%
+  \BA@colsepfalse
+  \BA@rulesepfalse
+  \BA@parse}
+%    \end{macrocode}
+%
+% "!" Just save the expression, and make "\BA@rulesepfalse" so that the
+% next "|" is not preceded by a skip.
+%    \begin{macrocode}
+\BA@defcolumntype{!}#1{%
+  \testBA@upart
+   {\GC@add@to@end\BA@l@expr{\BA@bdollar#1\BA@edollar}}%
+   {\GC@add@to@end\BA@r@expr{\BA@bdollar#1\BA@edollar}}%
+  \BA@rulesepfalse
+  \BA@parse}
+%    \end{macrocode}
+%
+% "*": "*{3}{xyz}" just produces "xyz*{2}{xyz}" which is then re-parsed.
+%    \begin{macrocode}
+\BA@defcolumntype{*}#1#2{%
+ \count@=#1\relax
+ \ifnum\count@>\z@
+    \advance\count@\m@ne
+    \edef\@tempa##1{\noexpand\BA@parse##1*{\the\count@}{##1}}%
+ \else
+    \def\@tempa##1{\BA@parse}%
+ \fi
+ \@tempa{#2}}
+%    \end{macrocode}
+%
+% "\BA@parseend" this is added to the end of the users preamble, it acts
+% like a cross between "#" and "&". It terminates the preamble building
+% as it does not call "\BA@parse".
+%    \begin{macrocode}
+\BA@defcolumntype{\BA@parseend}{%
+  \testBA@upart
+   {\BA@parse ##\BA@parseend}%
+   {%
+    \ifBA@colsep
+       \GC@add@to@front\BA@r@expr{\BA@edollar\hskip\BA@colsep}%
+    \else
+       \GC@add@to@front\BA@r@expr{\BA@edollar}%
+    \fi
+    \BA@expafter\xdef{blank@row}{\BA@use{blank@row}\omit\cr}%
+    \BA@add@rskip
+    \BA@col@expafter\GC@add@to@end{v\expandafter}\expandafter
+           {\BA@r@expr}}}
+%    \end{macrocode}
+%
+% Like {\tt array.sty}
+%    \begin{macrocode}
+\def\BA@startpbox#1{\bgroup
+  \hsize #1 \@arrayparboxrestore
+   \vrule \@height \ht\@arstrutbox \@width \z@}
+
+\def\BA@endpbox{\vrule \@width \z@ \@depth \dp \@arstrutbox \egroup}
+%    \end{macrocode}
+%
+% Save the "&" and "#" macros, so they can be restored after a
+% multicolumn, which redefines them.
+%    \begin{macrocode}
+\BA@stringafter{\let\expandafter\BA@save@amp}{&}
+\BA@stringafter{\let\expandafter\BA@save@hash}{#}
+%    \end{macrocode}
+%
+% A column specification of "\BAmulticolumn{3}{c}" is re-written to:\\
+% "c\BA@MC@end", except that the definition of "#" has been changed so
+% that it expands to:\\
+% ">{\null\span\span}\BA@MC@restore@hash&@{}&@{}\BA@MC@switch@amp"\\
+% The 2 "\span"s in the u-part make the entry span 3 columns, the 2
+% "&@{}" increment "\BA@col" without adding any intercolumn skips.
+% The "\BA@MC@restore@hash" specifier just restores "#" to its normal
+% meaning. "\BA@MC@switch@amp" then causes a specifier "&" to generate
+% an error, as the argument to multicolumn may only specify one column.
+% Finally when "\BA@MC@end" is reached, "&" is restored.
+%
+% "\BA@MC@restore@hash" restore the meaning of "#".
+%    \begin{macrocode}
+\BA@defcolumntype{\BA@MC@restore@hash}{%
+  \BA@stringafter\let{##}\BA@save@hash
+  \BA@parse}
+%    \end{macrocode}
+%
+% Switch the meaning of "&" so it generates an error, and skips all
+% specifiers up to "\BA@MC@end"
+%    \begin{macrocode}
+\BA@defcolumntype{\BA@MC@switch@amp}{%
+  \BA@stringafter\let{&}\BA@extra@amp
+  \BA@parse}
+%    \end{macrocode}
+%
+% Restore "&".
+%    \begin{macrocode}
+\BA@defcolumntype{\BA@MC@end}{%
+  \BA@stringafter\let{&}\BA@save@amp
+  \BA@parse}
+%    \end{macrocode}
+%
+% The special definition of "&" while parsing the multicolumn argument.
+%    \begin{macrocode}
+\def\BA@mc@extra@amp#1\BA@MC@end{%
+     \@latexerr{\string& in multicolumn!}\@ehc\BA@parse\BA@MC@end}%
+%    \end{macrocode}
+%
+% Putting it all together!
+%    \begin{macrocode}
+\BA@defcolumntype{\BAmulticolumn}#1#2{%
+  \BA@make@mc{#1}%
+  \BA@stringafter\let{##}\BA@mc@hash
+  \BA@parse#2\BA@MC@end}
+%    \end{macrocode}
+%
+% As explained above, in order to position the delimiters on the way
+% back we need the widths of the inter-column texts.
+%    \begin{macrocode}
+\def\BA@add@rskip{%
+  \BA@col@expafter\ifx{right}\relax\else
+    \setbox\BA@tempbox@a\hbox{\BA@bdollar\BA@r@expr}%
+    \BA@col@expafter\GC@add@to@end{right\expandafter}\expandafter
+       {\expandafter{\the\wd\BA@tempbox@a}}\fi}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@add@lskip{%
+  \BA@col@expafter\ifx{left}\relax\else
+    \setbox\BA@tempbox@a\hbox{\BA@l@expr\BA@edollar}%
+    \BA@col@expafter\GC@add@to@end{left\expandafter}\expandafter
+      {\expandafter{\the\wd\BA@tempbox@a}}\fi}
+%    \end{macrocode}
+%
+% \subsection{User Level Column-Type Definitions}
+%
+%    \begin{macrocode}
+\BAnewcolumntype{c}   {>{\hfil}<{\hfil}}
+\BAnewcolumntype{l}   {>{}<{\hfil}}
+\BAnewcolumntype{r}   {>{\hfil}<{}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\BAnewcolumntype[1]{p}{>{\vtop\BA@startpbox{#1}}c<{\BA@endpbox}}
+\BAnewcolumntype[1]{m}{>{$\vcenter\BA@startpbox{#1}}c<{\BA@endpbox$}}
+\BAnewcolumntype[1]{b}{>{\vbox\BA@startpbox{#1}}c<{\BA@endpbox}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\BAnewcolumntype{(}  {\Left{}{(}}
+\BAnewcolumntype{)}  {\Right{)}{}}
+\BAnewcolumntype{\{} {\Left{}{\{}}
+\BAnewcolumntype{\}} {\Right{\}}{}}
+\BAnewcolumntype{[}  {\Left{}{[}}
+\BAnewcolumntype{]}  {\Right{]}{}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\BAnewcolumntype{\BAenum}  {%
+  !{%
+    {\def\protect{\noexpand\protect\noexpand}%
+     \xdef\@currentlabel{\p@BAenumi\theBAenumi}}
+    \hbox to 2em{%
+    \hfil\theBAenumi}}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\BAnewcolumntype[1]{\BAmultirow}{>{\BA@mrow@bslash{#1}}##}
+%    \end{macrocode}
+%
+% \subsection{Footnotes}
+%
+% This test is true if footnote texts are to be displayed at the end of
+% the table.
+%    \begin{macrocode}
+\GC@newtest{BAtablenotes}
+\BAtablenotestrue
+%    \end{macrocode}
+%
+% Inside the alignment just save up the footnote text in a token
+% register.
+%    \begin{macrocode}
+\long\def\BA@ftntext#1{%
+  \edef\@tempa{\the\BA@ftn\noexpand\footnotetext
+                    [\the\csname c@\@mpfn\endcsname]}%
+  \global\BA@ftn\expandafter{\@tempa{#1}}}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\long\def\BA@xftntext[#1]#2{%
+  \global\BA@ftn\expandafter{\the\BA@ftn\footnotetext[#1]{#2}}}
+%    \end{macrocode}
+
+% \subsection{Hline and Hhline}
+% The standard "\hline" command would work fine `on the way down' but on
+% the way back it throws me into an infinite loop as there is no
+% "\lastrule" to move the rule into the final box. I could just make
+% "\hline" leave a code penalty, and put in the rule on the way back,
+% but this would mean that every array with an "\hline" needs to be
+% taken apart. I hope to make `most' arrays be possible without comming
+% back up the array via "\lastbox". I could do something with
+% "\leaders" which are removable, but for now, I just make "\hline" and
+% "\hline\hline" just call "\hhline" with the appropriate argument.
+% The "\hhline" from {\tt hhline.sty} does work, but needs extra options
+% to deal with "&" etc, but here is a re-implementation, more in the
+% spirit of this style.
+%
+%    \begin{macrocode}
+\def\BAhline{%
+  \noalign{\ifnum0=`}\fi
+   \futurelet\@tempa\BA@hline}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@hline{%
+  \ifx\@tempa\BAhline
+    \gdef\BA@hline@@##1{\BAhhline{*{\BA@col@max}{=}}}%
+  \else
+    \gdef\BA@hline@@{\BAhhline{*{\BA@col@max}{-}}}%
+  \fi
+  \ifnum0=`{\fi}%
+  \BA@hline@@}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BAhhline#1{%
+  \omit
+%    \end{macrocode}
+% First set up the boxes used in "\leaders".
+%    \begin{macrocode}
+\global\setbox\BA@ddashbox=\BA@HHbox\BAarrayrulewidth\BAarrayrulewidth
+\global\setbox\BA@dashbox=\hbox to \GC@six\BAarrayrulewidth{%
+  \hss
+  \vrule\@height\BAarrayrulewidth \@width\BAarrayrulewidth \@depth\z@
+  \hss}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+  \global\let\BA@strut\BA@strutB
+  \global\BA@rulesepfalse
+  \global\BA@uparttrue
+  \BA@HHparse#1\BA@HHend}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@HHexp#1#2{\expandafter#1\csname aa\string#2\endcsname}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@HHparse{{\ifnum0=`}\fi\BA@HHparsex}
+\def\BA@HHparsex#1{\BA@HHexp\aftergroup{#1}\ifnum0=`{\fi}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\BA@HHexp\def\BA@HHend{%
+  \cr}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\newbox\BA@dashbox
+\newbox\BA@ddashbox
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\BA@HHexp\def|{%
+  \ifBA@rulesep\hskip\BAdoublerulesep\fi
+  \global\BA@ruleseptrue
+  \vrule\@width\BAarrayrulewidth
+  \BA@HHparse}
+%    \end{macrocode}
+%
+% ":" denotes a broken vertical rule, as in "hhline.sty". If the double
+% dots \hbox{\leaders\hbox {\,:\,}\hskip3em} currently produced by
+% \verb|"| turn out to be useful, it might be better to use ":" for
+% them, and something else, perhaps "!" for this feature.
+%    \begin{macrocode}
+\BA@HHexp\def:{%
+  \ifBA@rulesep\hskip\BAdoublerulesep\fi
+  \global\BA@ruleseptrue
+  \copy\BA@ddashbox
+  \BA@HHparse}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\BA@HHexp\def-{%
+  \testBA@upart{}{&\omit\global\BA@uparttrue}%
+  \leaders\hrule\@height\BAarrayrulewidth\hfil
+  \global\BA@upartfalse
+  \global\BA@rulesepfalse
+  \BA@HHparse}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\BA@HHexp\def.{%
+  \testBA@upart{}{&\omit\global\BA@uparttrue}%
+  \copy\BA@dashbox\xleaders\copy\BA@dashbox\hfil\copy\BA@dashbox
+  \global\BA@rulesepfalse
+  \global\BA@upartfalse
+  \BA@HHparse}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\BA@HHexp\def"{%
+  \testBA@upart{}{&\omit\global\BA@uparttrue}%
+  \setbox\z@\hbox to \GC@six\BAarrayrulewidth
+       {\hss\copy\BA@ddashbox\hss}%
+  \copy\z@\xleaders\copy\z@\hfil\copy\z@
+  \global\BA@rulesepfalse
+  \global\BA@upartfalse
+  \BA@HHparse}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\BA@HHexp\def={%
+  \testBA@upart{}{&\omit\global\BA@uparttrue}%
+  \copy\BA@ddashbox\xleaders\copy\BA@ddashbox\hfil\copy\BA@ddashbox
+  \global\BA@rulesepfalse
+  \global\BA@upartfalse
+  \BA@HHparse}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\BA@HHexp\def~{%
+  \testBA@upart{}{&\omit\global\BA@uparttrue}%
+  \hfill
+  \global\BA@rulesepfalse
+  \global\BA@upartfalse
+  \BA@HHparse}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\BA@HHexp\def#{%
+  \ifBA@rulesep\hskip\BAdoublerulesep\fi
+  \global\BA@ruleseptrue
+  \vrule\@width\BAarrayrulewidth
+  \BA@HHbox\BAdoublerulesep\BAdoublerulesep
+  \vrule\@width\BAarrayrulewidth
+  \BA@HHparse}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\BA@HHexp\def{t}{%
+  \rlap{\BA@HHbox\BAdoublerulesep\z@}%
+  \BA@HHparse}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\BA@HHexp\def{b}{%
+  \rlap{\BA@HHbox\z@\BAdoublerulesep}%
+  \BA@HHparse}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\BA@HHbox#1#2{\vbox{%
+  \hrule \@height \BAarrayrulewidth \@width #1
+  \vskip \BAdoublerulesep
+  \hrule \@height \BAarrayrulewidth \@width #2}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\BA@HHexp\def&{&\omit\global\BA@uparttrue\BA@HHparse}
+%    \end{macrocode}
+%
+%
+%    \begin{macrocode}
+\BA@HHexp\def{*}#1#2{%
+ \count@=#1\relax
+ \ifnum\count@>\z@
+    \advance\count@\m@ne
+    \edef\next##1{\noexpand\BA@HHparse##1*{\the\count@}{##1}}%
+ \else
+    \def\next##1{\BA@HHparse}%
+ \fi
+ \next{#2}}
+%    \end{macrocode}
+%
+% \end{document}
+\endinput
diff --git a/macros/latex/contrib/blkarray/blkarray.tex b/macros/latex/contrib/blkarray/blkarray.tex
new file mode 100644
index 0000000000..f7f8f31e63
--- /dev/null
+++ b/macros/latex/contrib/blkarray/blkarray.tex
@@ -0,0 +1,2 @@
+\AtBeginDocument{\date{27 February 2015}}
+\input{blkarray.sty}