paracol (28jun13)

git-svn-id: svn://tug.org/texlive/trunk@31009 c570f23f-e606-0410-a88d-b1316a301751

5 files changed, 821 insertions, 270 deletions

diff --git a/Master/texmf-dist/source/latex/paracol/impl.dtx b/Master/texmf-dist/source/latex/paracol/impl.dtx
index 65fde3b5b83..8531e7b544d 100644
--- a/Master/texmf-dist/source/latex/paracol/impl.dtx
+++ b/Master/texmf-dist/source/latex/paracol/impl.dtx
@@ -558,6 +558,101 @@
 % denoted by $\Uidx\CST^c=(\Celt^c,\celt_1,\ldots,\celt_n)$ which we
 % rewind\slash reestablish at each out-of-order jump in the column $c$.
 % 
+% Now we have to pay attention to the fact a coloring command can appear in
+% horizontal mode of course, and thus push/pop operations in a \colpage{}
+% would be done {\em before} the \colpage{} starts when \!\set@color! or
+% \!\reset@color! is in the second half of a page-crossing paragraph and if
+% we immediately performed push\slash pop of the \colorstack{} in these
+% macros.  In addition, even in vertical mode these macros can appear before
+% a page break after which they must be in effect, if they are preceded by a
+% vertical item to make a break before it and an inhibiting penalty 10000
+% which {\em delays} \TeX{} examining the break and thus invoking \!\output!.
+% 
+% In order to solve the problem of push/pop timing, we maintain a list
+% $\Uidx{\cstb}={}$\!\pcol@colorstack@buf!
+% 

+% \SpecialMainIndex{\pcol@colorstack@buf}

+% 

+% of colors to be pushed in $\cst$, and raise a special \!\output!
+% request, via \!\vadjust! if in horizontal mode, for \colorstack{}
+% manipulation rather than performing it immediately.  That is, at the
+% request itself or at the completion of the paragraph having these macros,
+% we have a sequence of \!\output! requests for pushes and pops toghether
+% with the list $\cstb$ for pushes, and possibly a request for a page break
+% in the sequence or at its tail and/or that for \cswitch{} at the tail.
+% Since a request for push moves the first element of $\cstb$ to the tail of
+% $\cst$ while that for pop simply pops $\cst$, \!\output! for a page
+% break or \cswitch{} should see $\cst$ perfectly consistent with coloring
+% \!\special!s in the main vertical list given to the \!\output!.
+% 
+% The mechanism above especially for horizontal mode has subtle issues as
+% follows.
+% 

+% \begin{itemize}
+% \item
+% If \!\set@color! appears in a \!\vbox!, the \!\output! request for pushing
+% is not effective but corresponding \!\reset@color! can be outside of the
+% \!\vbox! to make pushes and pops unbalanced because \!\aftergroup! for it
+% inserts it just after the closing of the \!\vbox! if \!\set@color! is not
+% surrounded by an inner group.  Another problem with this ineffective
+% \!\output! request is that the {\em protection} by a dummy request of
+% $-10004$ and an empty \!\vbox! from the elimination just after a page
+% break should causes a trouble by the latter because the empty \!\vbox!
+% is added to the \!\vbox! in question.
+% 
+% \item
+% If we are in vertical mode, we can know if we are in a \!\vbox! by
+% \CSIndex{ifinner}.  However, in horizontal or math mode, \CSIndex{ifinner}
+% cannot help us because it is true iff we are in a \!\hbox! or in an
+% in-text math.  In short, \TeX{} does not provide us with any convenient
+% means to know if we are in a \!\vbox!.
+% \end{itemize}
+% 

+% To solve the problem above, we introduced a trick with \!\everyvbox! to
+% turn a switch $\CSIndex{ifpcol@inner}=\true$ at the beginning of every
+% \!\vbox! in a \env{paracol} environment, by which we supress the
+% \!\output!  request for \!\set@color! because a \!\vbox! cannot cross a
+% page boundary.  As for that of \!\reset@color!, we suppress it by not
+% reserving our own macro \!\pcol@reset@color@pop! for the request by
+% \!\aftergroup!.  That is, we reserve both \!\reset@color! and
+% \!\pcol@reset@color@pop! with \!\aftergroup! if we are outside of any
+% \!\vbox!es, while does the former only otherwise.  By the same reason, we
+% supress the requests if we are in restricted horizontal mode, i.e., if
+% both \CSIndex{ifhmode} and \CSIndex{ifinner} are true.  On the other hand,
+% we cannot supress the request when we are in an in-text math because it
+% can cross a page boundary\footnote{

+% 

+% If an in-text math is in a \!\hbox!, making the \!\output! request is not
+% necessary because the math cannot cross a page boundary.  Though we can
+% detect it by a trick with \!\everyhbox!, we abandon this idea because the
+% request is not harmful.}.
+% 

+% Note that the detailed implementation shown in \secref{sec:imp-startenv}
+% does not interfere the use of \!\everyvbox! inside/outside of
+% \env{paracol} environments or is not affected by the use.
+% 
+% The implemntation of \!\columncolor! and \!\normalcolumncolor! has issues
+% similar to above but a little bit more complicated because we need to
+% update $\Celt^c$ at the bottom of \colorstack{} if we are in the column
+% $c$.  That is, in addition to adding the specified color to the tail of
+% $\cstb$ and making a special \!\output! request for update, we need to
+% rewind the stack before updating $\Celt^c$ and then reestablish the stack
+% with the updated $\Celt^c$.  A complication is in the fact that the
+% \colorstack{} $\cst$ may not be up-to-date at the occurence of the
+% commands.  More complicatedly, the existence of $\Celt^c$ itself is not
+% up-to-date because we have to update it by the special \!\output! request.
+% This problem is solved by having {\em shadows} of $\cst$ and $\Celt^c$,
+% namely {$\Uidx{\cstshadow}=\Midx{\!\pcol@colorstack@shadow!}$} and
+% $\Uidx{\Celtshadow^c}=|\pcol@columncolor@shadow|{\cdot}c$,
+% 

+% \SpecialArrayMainIndex{c}{\pcol@columncolor@shadow}
+% 

+% into which we push or set a color immediately, and referring to them for
+% rewinding and reestablishing the up-to-date \colorstack{} in the
+% column-color commands.  Note that the shadows are referred to only outside
+% \!\output! routine and thus popping is done automatically by doing push
+% operations locally.
+% 
 % The fundamental mechanism above works well with respect to coloring, but
 % it has a problem that a \colpage{} created by, for example, a forced page
 % break may not be perfectly empty but can have some coloring \!\special!s
@@ -593,7 +688,10 @@
 % \lpage, the \colorstack{} in |.dvi| should be empty.  Therefore to avoid
 % stack underflow, we should reestablish $\cst$ (not $\CST^c$) so that
 % elements in the stack are popped by \!\reset@color! invoked with the
-% \!\aftergroup! mechanism.
+% \!\aftergroup! mechanism.  We also take care of our own \colorstack{}
+% popper \!\pcol@reset@color@pop! which must do nothing, i.e., must not make
+% a \!\output! request, after we completed the \lpage, i.e.,
+% if \CSIndex{ifpcol@output} is $\false$.
 % 
 % 
 % 
@@ -722,6 +820,12 @@
 % \subsubsection{Integer Registers}
 % 
 % \begin{description}
+% \item[\Uidx{\!\deadcycles!}]
+% is \TeX's primitive register to count the number of \!\output! requests
+% made between two \!\shipout! operatios.  It is zero-cleared by
+% \!\pcol@invokeoutput! because it can have a large number in a
+% \env{paracol} environment.
+% 
 % \item[\Uidx{\!\outputpenalty!}]
 % is \TeX's primitive register to have the page-break penalty with which
 % \!\output! routine is invoked.  It is referred to by \!\pcol@output! to
@@ -736,12 +840,13 @@
 % is \TeX's primitive register to have the page-break penalty inserted
 % between two lines.  The register is referred to in \!\pcol@output@start!
 % to make \Preenv{} \Mgfnote{}s followed by this \!\penalty! on the
-% \!\insert!ion, in \!\pcol@restartcolumn!  to insert the \!\penalty! in the
-% register to resume a \colpage{} unless it is suspended after a sectioning
-% command, i.e., $\CSIndex{if@nobreak}=\true$, in \!\pcol@deferredfootins!
-% to let the secnod half of split $\df$ have this \!\penalty! as the very
-% first element, in \!\pcol@fntexttop!\marg{text} to make the footnote
-% $\arg{text}$ followed by this \!\penalty! on the \!\insert!ion, in
+% \!\insert!ion, in \!\pcol@restartcolumn! and \!\pcol@return@from@color! to
+% insert the \!\penalty! in the register to resume a \colpage{} unless it is
+% suspended after a sectioning command, i.e., $\CSIndex{if@nobreak}=\true$,
+% in \!\pcol@deferredfootins!  to let the secnod half of split $\df$ have
+% this \!\penalty! as the very first element, in
+% \!\pcol@fntexttop!\marg{text} to make the footnote $\arg{text}$ followed
+% by this \!\penalty! on the \!\insert!ion, in
 % \!\pcol@fntextother!\marg{text} to make the footnote $\arg{text}$ preceded
 % by this \!\penalty! in $\df$, and in \!\pcol@fntextbody! to let it have
 % \!\interfootnotelinepenalty!.
@@ -828,10 +933,10 @@
 % \item[\Uidx{\!\@Miv!}]
 % is a \!\mathchardef! register to have 10004.  It is used in \!\pcol@output!
 % to examine if $\!\outputpenalty!=-10004$ for a dummy \!\output! request
-% made by \LaTeX's float-related macros and our \!\pcol@invokeoutput! to
-% ensure the real request is not eliminated when it is made at the very
-% beginning of a page or a \colpage.  It is also used in
-% \!\pcol@specialoutput! for footnote logging when
+% made by \LaTeX's float-related macros and our \!\pcol@invokeoutput! and
+% \!\pcol@color@invokeoutput! to ensure the real request is not eliminated
+% when it is made at the very beginning of a page or a \colpage.  It is also
+% used in \!\pcol@specialoutput! for footnote logging when
 % $\!\outputpenalty!=-10004$.
 % 
 % \item[\Uidx{\!\@MM!}]
@@ -1218,6 +1323,7 @@
 % \!\pcol@output@start!,
 % \!\pcol@output@switch!,
 % \!\pcol@setcurrcol!,
+% \!\pcol@color@invokeoutput!,
 % \!\pcol@sync!,
 % \!\pcol@synccolumn!,
 % \!\pcol@makeflushedpage!,
@@ -1646,8 +1752,10 @@
 % is a \!\box! register to have the main vertical list when \!\output! is
 % invoked with a special \!\penalty! code.  It is let have that by
 % \!\pcol@specialoutput!, and is referred to by \!\pcol@output@start! to
-% have its height and depth, by \!\pcol@makenormalcol! for \preenv{}, and by
-% \!\pcol@output@switch! for the column from which we are leaving.
+% have its height and depth, by \!\pcol@makenormalcol! for \preenv{}, by
+% \!\pcol@output@switch! for the column from which we are leaving, and by
+% \!\pcol@return@from@color! to put its contents back to the main vertical
+% list.
 % 
 % \item[\Uidx{\!\@outputbox!}]
 % is a \!\box! register to have a partial or the complete ship-out image
@@ -1754,6 +1862,16 @@
 % or that simply given in a column are saved into $\cc_c(\ep)$ by
 % \!\pcol@setcurrcol!, and then restored from it by \!\pcol@iigetcurrcol!.
 % 
+% \item[\Uidx{\!\everyvbox!}]
+% is \TeX's primitive to have tokens inserted at the beginning of each
+% \!\vbox!.  In \!\paracol!, after tokens in it are saved into
+% \!\pcol@everyvbox!, it is let have a \!\the!-reference to
+% \!\pcol@everyvbox! and |\pcol@innertrue| to turn
+% $\CSIndex{ifpcol@inner}=\true$, and then the register itself is made
+% \!\let!-equal to \!\pcol@everyvbox!.  In addition, it is let have tokens
+% in \!\pcol@everyvbox! if a \!\global! assignment to the register is made
+% in the \env{paracol} just having been closed.
+% 
 % \item[\Uidx{\!\@temptokena!}]
 % is a \!\toks! register for temporary use.  It is used in
 % \!\pcol@output@switch! to broadcast \!\everypar! to $\cc_c(\ep)$ for all
@@ -1786,8 +1904,8 @@
 % \CSIndex{if@afterindent} by \!\pcol@setcurrcol!, and then restored from
 % it by \!\pcol@iigetcurrcol!.  The macro \!\pcol@output@switch! refers to
 % it to broadcast its value set by a \mctext{} to $\cc_c(\sw)$ for all
-% $c\In0\C$.  The \!\pcol@restartcolumn! inserts $\!\penalty!=10000$ by
-% \!\nobreak! if the switch is $\true$.
+% $c\In0\C$.  The \!\pcol@restartcolumn! and \!\pcol@return@from@color!
+% insert $\!\penalty!=10000$ by \!\nobreak! if the switch is $\true$.
 % 
 % \item[\Uidx{\CSIndex{if@afterindent}}]
 % is a switch to be $\true$ iff a sectioning commmand tells that the fisrt
@@ -1974,15 +2092,16 @@
 % 
 % \item[\Uidx{\!\nobreak!}]
 % is an API macro to insert $\!\penalty!=10000$ to inhibit line or page
-% breaks.  It is used in \!\pcol@restartcolumn! to meet the page-break
-% inhibition request made by $\CSIndex{if@nobreak}=\true$.
+% breaks.  It is used in \!\pcol@restartcolumn! and
+% \!\pcol@return@from@color! to meet the page-break inhibition request made
+% by $\CSIndex{if@nobreak}=\true$.
 % 
 % \item[\Uidx{$\!\addpenalty!\arg{pen}$}]
 % is an API macro to insert a page break $\!\penalty!=\arg{pen}$ if
 % $\CSIndex{if@nobreak}={\false}$.  The \!\penalty! is inserted removing the
 % last vertical skip which is reinserted after the \!\penalty!.  The macro
-% is used in \!\pcol@restartcolumn! to insert \!\interlinepenalty! if
-% $\CSIndex{if@nobreak}=\false$.
+% is used in \!\pcol@restartcolumn! and \!\pcol@return@from@color! to insert
+% \!\interlinepenalty! if $\CSIndex{if@nobreak}=\false$.
 % 
 % \item[\Uidx{\!\footnotesize!}]
 % is an API macro to set the font size for footnotes.  It is used in
@@ -2078,9 +2197,10 @@
 % \item[\Uidx{$\!\PackageWarning!\arg{pkg}\arg{msg}$}]
 % is a developer's API macro to report a warning message $\arg{msg}$ with
 % the package identification $\arg{pkg}$.  The macro is used in
-% \!\pcol@ignore!  to complain an API macro appears in \env{paracol}
-% inappropriately, and in \!\pcol@fntextbody! if the footnote is taller than
-% $\!\textheight!-\!\skip!\!\footins!$.
+% \!\pcol@icolumncolor! to complain \!\columncolor! or \!\normalcolumncolor!
+% is used in an ineffective situation, \!\pcol@ignore! to complain an API
+% macro appears in \env{paracol} inappropriately, and in \!\pcol@fntextbody!
+% if the footnote is taller than $\!\textheight!-\!\skip!\!\footins!$.
 % 
 % \item[\Uidx{\!\@@par!}]
 % is an internal macro to keep \TeX's original primitive \CSIndex{par} in it.
@@ -2360,8 +2480,11 @@
 % and its footnotes $\cc_c(\ft)$ if any, to \!\@freelist!.
 % 
 % \item
-% \!\pcol@set@color@push! to push $\celt$ in \!\current@color! to the
-% \colorstack{} $\cst=\!\pcol@colorstack!$.
+% \!\pcol@set@color@push! to push $\gamma$ in \!\current@color! to the
+% \colorstack{} pushing list $\cstb=\!\pcol@colorstack@buf!$.
+% 
+% \item
+% \!\pcol@output@icpush! to push $\gamma$ at the head of $\cstb$ into $\cst$.
 % 
 % \item
 % $\!\pcol@reset@color@elt!\!\@elt!\Arg{\celt_i}\!\@elt!\Arg{\celt_{i+1}}$ to
@@ -2449,16 +2572,18 @@
 % original definition is saved in \!\pcol@set@color! while the macro itself
 % is made \!\let!-equal to \!\pcol@set@color@push!.  The macro
 % \!\pcol@icolumncolor! also refers to it to examine the color package
-% provision, and if so temporarily lets it be \!\relax! so that \!\color!
-% invoked in the macro just defines \!\current@color! without doing any
-% other coloring operations.
+% provision, and if so its descendent \!\pcol@iicolumncolor! temporarily
+% lets it be \!\relax! so that \!\color! or \!\normalcolor! invoked in the
+% macro just defines \!\current@color! without doing any other coloring
+% operations.  On the other hand, \!\pcol@output! makes it \!\let!-equal to
+% \!\pcol@set@color!, i.e., lets it regain its original definition because
+% we don't need any special operations in \!\output! routine.
 % 
 % \item[\Uidx{\!\reset@color!}]
 % is an internal macro to finish text coloring started by \!\set@color!.  By
 % default it is undefined but may have some definition to put a \!\special!
-% to finish coloring.  In \!\paracol!, its original definition is saved in
-% \!\pcol@reset@color! while the macro itself is made \!\let!-equal to
-% \!\pcol@reset@color@pop!.
+% to finish coloring.  It is used in \!\pcol@clearcolorstack! so as to apply
+% it to all elements in $\CST^c$.
 % 
 % \item[\Uidx{\!\color@begingroup!}]
 % is an internal macro to open a group in which a color is specified.  It is
@@ -2544,6 +2669,12 @@
 % \colpage{}, in \!\pcol@flushcolumn! for a \ccolpage{} to be flushed, and
 % in \!\pcol@makeflushedpage! for \colpage{}s in $\ptop$ to be flushed.
 % 
+% \item[\Uidx{\!\@reinserts!}]
+% in an internal macro for \!\output! routine to put \!\footins! and
+% \!\@kludgeins! back to the main vertical list if they have something.  It
+% is used in \!\pcol@return@from@color! to go back to the building process
+% of the main vertical list as if it is not interrupted.
+% 
 % \item[\Uidx{\!\@combinefloats!}]
 % is an internal macro for \!\output! routine to combine top and bottom
 % floats in \!\@toplist! and \!\@botlist! respectively with \!\@outputbox!
@@ -2738,15 +2869,30 @@
 % $\cc_c(\bl)=\!\@botlist!$  and $\cc_c(\dl)=\!\@deferlist!$.
 % 
 % \item
-% \!\pcol@reset@color@pop! does $\!\@elt!=\!\pcol@reset@color@elt!$ to
-% remove the tail of \colorstack{} $\cst=\!\pcol@colorstack!$.
+% \!\pcol@set@color@push! does $\!\@elt!=\!\relax!$ to push a color
+% information into $\cstshadow$, with save\slash restore of its original
+% value.
+% 
+% \item
+% \!\pcol@icolumncolor! does $\!\@elt!=\!\relax!$ to \!\xdef!ine
+% $\Celt^c=|\pcol@columncolor|{\cdot}\~c$,
+% $\Celtshadow^c=|\pcol@columncolor@shadow|{\cdot}\~c$ and
+% $\cstb=\!\pcol@colorstack@buf!$ in \!\pcol@iicolumncolor!.
+% 

+% \SpecialArrayIndex{c}{\pcol@columncolor}

+% \SpecialArrayIndex{c}{\pcol@columncolor@shadow}

 % 
 % \item
-% \!\pcol@reset@color@elt! uses \!\@elt! for recursive invocatoin of itself.
+% \!\pcol@output@icpush! and \!\pcol@output@icset! have \!\@elt! in their
+% argument specifications to pick the first element of $\cstb$.
 % 
 % \item
-% \!\pcol@clearcolorstack! does $\!\@elt!=\!\pcol@reset@color!$ for
-% $\celt_i$ in $\CST^c$ to rewind printer's \colorstack.
+% \!\pcol@output@cpop! uses \!\@elt! to invoke \!\pcol@reset@color@elt!,
+% which also uses it for recursive invocatoin of itself.
+% 
+% \item
+% \!\pcol@clearcolorstack! does $\!\@elt!=\!reset@color!$ for $\celt_i$ in
+% $\CST^c$ to rewind printer's \colorstack.
 % 
 % \item
 % \!\pcol@restorecst!$\<\mathit{\Gamma}'\>$ does
@@ -2759,12 +2905,6 @@
 % $\csts$.
 % 
 % \item
-% \!\pcol@icolumncolor! does $\!\@elt!=\!\relax!$ to \!\xdef!ine
-% $\Celt^c=|\pcol@columncolor|{\cdot}\~c$.

-% 

-% \SpecialArrayIndex{c}{\pcol@columncolor}

-% 
-% \item
 % \!\pcol@makefcolumn! does $\!\@elt!=\!\pcol@makefcolelt!$ for (the copy
 % of) $\cc_c(\dl)$ to examine if each float in it can be put in a \fcolumn{}
 % to be built, and then \!\def!ine it to put floats in $\cc_c(\tl)$ into
@@ -2781,8 +2921,7 @@
 % 
 % \item
 % \!\pcol@output@end! does $\!\@elt!=\!\relax!$ to add the \spanning{} of
-% the last page to the head of \!\@dbldeferlist!, and then
-% $\!\@elt!=\!\pcol@reset@color!$ to apply it to $\Celt^c$.
+% the last page to the head of \!\@dbldeferlist!.
 % 
 % \item
 % \!\paracol! does $\!\@elt!=\!\pcol@remctrelt!$ for $\CG$,
@@ -2947,10 +3086,12 @@
 % \item[\Uidx{\!\@nil!}]
 % is an internal control sequence which is conventionally used to terminate
 % a variable length argument.  It is used in \!\pcol@getcurrpinfo! for the
-% invocation of \!\@cdr!, in \!\pcol@reset@color@pop! as the tail sentinel
-% of the \colorstack{} $\cst$ temporarily stored in \!\reserved@a!, and in
-% \!\pcol@iadjustfnctr! and \!\pcol@iifootnotetext! to terminate their
-% argument |[|$[|+-|]\meta{disp}$|]| passed to \!\pcol@calcfnctr!.
+% invocation of \!\@cdr!, in \!\pcol@output@cpush! and \!\pcol@output@cset!
+% to remove the first element of $\cstb$ by \!\pcol@output@icpush! and
+% \!\pcol@output@icset! respectively, in \!\pcol@output@cpop! to terminate
+% $\cst$, and in \!\pcol@iadjustfnctr! and \!\pcol@iifootnotetext! to
+% terminate their argument |[|$[|+-|]\meta{disp}$|]| passed to
+% \!\pcol@calcfnctr!.
 % 
 % \item[\Uidx{\!\@nnil!}]
 % is an internal macro having \!\@nil!.  It is referred to by
@@ -2960,8 +3101,8 @@
 % \item[\Uidx{\!\current@color!}]
 % is an internal macro having color information to be put into |.dvi| as a
 % part of the argument of coloring \!\special!.  It is referred to by
-% \!\pcol@set@color@push!, \!\pcol@set@color@elt!  and
-% \!\pcol@icolumncolor!.
+% \!\pcol@set@color@push!, \!\pcol@set@color@elt!,
+% \!\pcol@icolumncolor! and \!\pcol@iicolumncolor!.
 % 
 % \item[\Uidx{\!\@dbldeferlist!}]
 % is an internal macro having the list of page-wise floats whose page
@@ -3092,9 +3233,14 @@
 % to broadcast it to other columns.
 % 
 % \item
-% In \!\pcol@reset@color@pop!, it has $\cst$ so that we redefine
-% \!\pcol@colorstack! removing its tail applying \!\pcol@reset@color@elt! to
-% each element $\celt_i$.
+% In \!\pcol@getshadowcc!, it is used implement
+% $\!\let!|\pcol@columncolor|{\cdot}c=|\pcol@|\~|columncolor@shadow|{\cdot}c$.
+% 

+% \SpecialArrayIndex{c}{\pcol@columncolor}

+% \SpecialArrayIndex{c}{\pcol@columncolor@shadow}

+% 
+% \item
+% In \!\pcol@output@cpop!, it has $\cst$ from which we remove its tail.
 % 
 % \item
 % In \!\pcol@ifempty!$\arg{box}\arg{then}\arg{else}$, it has $\arg{then}$ or
@@ -3262,10 +3408,12 @@
 % \!\pcol@output@switch!,
 % \!\pcol@getcurrcol!,
 % \!\pcol@setcurrcol!,
-% \!\pcol@clearcolorstack!,
-% \!\pcol@restorecolorstack!,
 % \!\pcol@columncolor!,
 % \!\normalcolumncolor!,
+% \!\pcol@icolumncolor!,
+% \!\pcol@output@icset!,
+% \!\pcol@clearcolorstack!,
+% \!\pcol@restorecolorstack!,
 % \!\pcol@invokeoutput!\footnote{

 % 

 % Only for logging.},
@@ -3712,6 +3860,20 @@
 % \!\pcol@outputelt!, \!\pcol@makeflushedpage!, \!\pcol@flushfloats!,
 % \!\paracol!, \!\pcol@mctext! and \!\pcol@switchcol! if it is $\true$.
 % \end{macro}
+% 

+% \begin{macro}{\ifpcol@inner}
+% \changes{v1.22}{2013/06/30}
+%	{Introduced to know if we are in a \cs{vbox}.}

+% 

+% The switch \cs{ifpcol@inner} is turned $\false$ by \!\paracol! to mean we
+% are outside any \!\vbox!es, while the macro also lets \!\everyvbox! in the
+% \env{paracol} environment has the operation to turn the switch $\true$ so
+% that it is true whenever we are in a \!\vbox!.  The switch is examined by
+% \!\pcol@set@color@push! and \!\pcol@icolumncolor!, the former of which
+% also turned it $\true$ if we are in restricted horizontal mode, to make an
+% \!\output! request for \colorstack{} manipuratoin and, in the former, to
+% reserve the stack popper by \!\aftergroup!, iff the switch is $\true$.
+% \end{macro}
 % 
 %    \begin{macrocode}
 \newif\ifpcol@output \global\pcol@outputfalse
@@ -3727,6 +3889,7 @@
 \newif\ifpcol@mgfnote \pcol@mgfnotefalse
 \newif\ifpcol@fncounteradjustment \pcol@fncounteradjustmentfalse
 \newif\ifpcol@swapcolumn \global\pcol@swapcolumnfalse
+\newif\ifpcol@inner
 %    \end{macrocode}
 % 
 % 
@@ -3830,7 +3993,7 @@
 % 
 % \subsection{\cs{box} Register}
 % 
-% The last declaration is for the following \!\box! register.
+% The next declaration is for the following \!\box! register.
 % 

 % \begin{macro}{\pcol@topfnotes}
 % \changes{v1.2-2}{2013/05/11}
@@ -3852,6 +4015,32 @@
 % 

 %    \begin{macrocode}
 \newbox\pcol@topfnotes
+%    \end{macrocode}
+% 
+% 
+% 
+% \subsection{\cs{toks} Register}
+% 
+% The last declaration is for the following \!\toks! register.
+% 

+% \begin{macro}{\pcol@everyvbox}
+% \changes{v1.22}{2013/06/30}
+%	{Introduced to keep \cs{everyvbox} work as usual while having
+%	 \cs{pcol@innertrue} in it always.}
+% 

+% The register \!\pcol@everyvbox! acts as \!\everyvbox! in \env{paracol}
+% environments.  That is, by \!\paracol!, \!\everyvbox! is made
+% \!\let!-equal to this register so that updates and references of
+% \!\everyvbox! is made to this register, while the real \!\everyvbox! is
+% let have the reference to the register and |\pcol@innertrue| to make
+% $\CSIndex{ifpcol@inner}=\true$ in every \!\vbox!.  Besides \!\paracol!,
+% the register is reffered to by \!\pcol@restoreeveryvbox! to examine if it
+% has been \!\global!ly updated, i.e., its contents is not
+% \!\pcol@dummytoken!.
+% \end{macro}
+% 

+%    \begin{macrocode}
+\newtoks\pcol@everyvbox
 
 %    \end{macrocode}
 % 
@@ -3873,7 +4062,7 @@
 % intentionally.
 % \end{macro}
 % 

-% \vskip15\baselineskip\vskip-15\baselineskip
+% \par\vskip15\baselineskip\vskip-15\baselineskip
 % \begin{macro}{\pcol@LogLevel}
 % \changes{v1.2-2}{2013/05/11}
 %	{Introduced for debugging single-columned footnote functions.}

@@ -4030,6 +4219,18 @@
 % 

 % \begin{itemize}
 % \item
+% \changes{v1.22}{2013/06/30}
+%	{Add resetting \cs{set@color}.}

+% \!\set@color! is made \!\let!-equal to \!\pcol@set@color!, i.e, it regains
+% its original definition, throughout \!\output! routine, because no
+% manipulation of \colorstack{} is necessary\footnote{

+% 

+% Though this operation is not necessary because \cs{everyvbox} should work
+% for any \cs{set@color} because they should be in a \cs{vbox}, we dare to
+% do it for clearity.}.
+% 

+% 
+% \item
 % $\!\@specialoutput!\to\!\pcol@specialoutput!$ to process \Paracol's own
 % special output functions, starting first page, \cswitch, page
 % flushing with\slash without float flusing, and building the multi-column
@@ -4101,8 +4302,9 @@
 % refers to the value in \!\@maxdepth!.
 % 

 %    \begin{macrocode}
-\def\pcol@output{\let\par\@@par
-  \pcol@Logstart{\pcol@output\number\outputpenalty}%
+\def\pcol@output{\let\par\@@par \let\set@color\pcol@set@color
+  \pcol@Logstart{\pcol@output\number\outputpenalty
+    (\number\c@page:\number\pcol@currcol)}%
   \ifnum\outputpenalty<-\@M
     \pcol@specialoutput
   \else\ifpcol@output
@@ -5083,22 +5285,37 @@
 % \begin{macro}{\pcol@op@flush}
 % \begin{macro}{\pcol@op@clear}
 % \begin{macro}{\pcol@op@end}
+% \begin{macro}{\pcol@op@cpush}
+% \changes{v1.22}{2013/06/30}
+%	{Introduced for output request to push color stack.}

+% \begin{macro}{\pcol@op@cpop}
+% \changes{v1.22}{2013/06/30}
+%	{Introduced for output request to pop color stack.}

+% \begin{macro}{\pcol@op@cset}
+% \changes{v1.22}{2013/06/30}
+%	{Introduced for output request to set $\gamma_0^c$}

+% 

 % The macro $|\pcol@op@|{\cdot}f$ where $f\in
-% F=\{|start|,|switch|,|flush|,|clear|,|end|\}$ has our own
-% \!\outputpenalty! code less than $-10000$ to invoke the corresponding
-% macro $|\pcol@output@|{\cdot}f$.  The code macros are given to
-% \!\pcol@invokeoutput! as its argument by \!\paracol! ($f=|start|$),
+% F=\{|start|,|switch|,|flush|,|clear|,|end|,|cpush|,|cpop|,|cset|\}$ has
+% our own \!\outputpenalty! code less than $-10000$ to invoke the
+% corresponding macro $|\pcol@output@|{\cdot}f$.  The code macros are given
+% to \!\pcol@invokeoutput! as its argument by \!\paracol! ($f=|start|$),
 % \!\pcol@switchcol! ($f=|switch|$), \!\pcol@visitallcols! ($f=|switch|$),
 % \!\pcol@com@flushpage! ($f=|flush|$), \!\pcol@com@clearpage!
-% ($f=|clear|$), \!\pcol@flushclear! ($f=|switch|$), and \!\endparacol!
-% ($f=|end|$) to set one of them into \!\outputpenalty!, so that the other
+% ($f=|clear|$), \!\pcol@flushclear! ($f=|switch|$), \!\endparacol!
+% ($f=|end|$), \!\pcol@set@color@push! ($f=|cpush|$),
+% \!\pcol@reset@color@pop!  ($f=|cpop|$), and \!\pcol@icolumncolor!
+% ($f=|cset|$) to set one of them into \!\outputpenalty!, so that the other
 % user \!\pcol@specialoutput! examines which special function is invoked.

 % 

 % \SpecialIndex{\pcol@output@start}

 % \SpecialIndex{\pcol@output@switch}

 % \SpecialIndex{\pcol@output@flush}

 % \SpecialIndex{\pcol@output@clear}

-% \SpecialIndex{\pcol@output@end}
+% \SpecialIndex{\pcol@output@end}

+% \SpecialIndex{\pcol@output@cpush}

+% \SpecialIndex{\pcol@output@cpop}

+% \SpecialIndex{\pcol@output@cset}
 % 

 %    \begin{macrocode}
 %% Special Output Routines: Dispatcher
@@ -5108,14 +5325,22 @@
 \def\pcol@op@flush{-10012}
 \def\pcol@op@clear{-10013}
 \def\pcol@op@end{-10014}
+\def\pcol@op@cpush{-10015}
+\def\pcol@op@cpop{-10016}
+\def\pcol@op@cset{-10017}
 %    \end{macrocode}
 % \end{macro}\end{macro}\end{macro}\end{macro}\end{macro}
+% \end{macro}\end{macro}\end{macro}
 % 

 % \begin{macro}{\pcol@specialoutput}
 % \changes{v1.0}{2011/10/10}
 %	{Remove unnecessary \cs{pcol@latex@specialoutput}.}

 % \changes{v1.2-2}{2013/05/11}
 %	{Add footnote logging if $\cs{outputpenalty}\EQ-10004$.}

+% \changes{v1.22}{2013/06/30}
+%	{Add the invocation of \cs{pcol@output@}${\cdot}f$ for
+%	 $f\in\{\string\texttt{cpush},\string\texttt{cpop},
+% 	 \string\texttt{cset}\}$}
 % 

 % The macro \!\pcol@specialoutput! is invoked solely in \!\pcol@output! to
 % invoke our own or \LaTeX's special output routine.  It examines if
@@ -5146,11 +5371,17 @@
     \let\reserved@a\pcol@output@clear
   \else\ifnum\outputpenalty=\pcol@op@end\relax
     \let\reserved@a\pcol@output@end
+  \else\ifnum\outputpenalty=\pcol@op@cpush\relax
+    \let\reserved@a\pcol@output@cpush
+  \else\ifnum\outputpenalty=\pcol@op@cpop\relax
+    \let\reserved@a\pcol@output@cpop
+  \else\ifnum\outputpenalty=\pcol@op@cset\relax
+    \let\reserved@a\pcol@output@cset
   \else \let\reserved@a\@specialoutput
-  \fi\fi\fi\fi\fi
+  \fi\fi\fi\fi\fi\fi\fi\fi
   \ifnum\outputpenalty=-\@Miv\relax
-    \ifvoid\footins\else \pcol@Log\dummy{dummy}\footins
-  \fi\fi
+    \ifvoid\footins\else \pcol@Log\dummy{dummy}\footins \fi
+  \fi
   \ifx\reserved@a\@specialoutput\else
     \global\setbox\@holdpg\vbox{\unvbox\@holdpg \unvbox\@cclv
       \setbox\@tempboxa\lastbox \unskip}%
@@ -5338,26 +5569,27 @@
 % \changes{v1.2-2}{2013/05/11}
 %	{Add insertion of \cs{footins} having footnotes to be merged if it
 %	 is not void.}

+% \changes{v1.22}{2013/06/30}
+%	{Move emptying \cs{pcol@colorstack} to \cs{paracol}.}
 % 

 % Finally, we let $c=\!\pcol@currcol!=0$ for the first column, and regain the
 % parameters in $\cc_0$ by \!\pcol@getcurrcol!.  Then before putting
 % $\cc_0(\vb^b)$ to the main vertical list by \!\unvbox! returning
 % $\cc_0(\vb)$ to \!\@freelist! by \!\@cons! because it has become useless
-% so far, we let the \colorstack{} $\cst$ empty and save the \colorctext{}
-% just with $\Celt^0$ into $\csts$ by \!\pcol@savecolorstack!.  Then we
-% \!\insert! \!\footins! through itself to the main vertical list if it
-% is not $\bot$ and thus has footnotes to be \mgfnote{}.  This \!\insert!ion
-% is different from other footnote \!\insert!ion because \!\footins! is not
-% \!\unvbox!ed but is put as a whole and is followed by
-% \!\penalty!\!\interlinepenalty!, so that footnotes will not be broken by
-% \TeX's page builder to prevent the reconnection of a broken footnote with
-% innapropriate glue discarding, which we will discuss in
-% \secref{sec:imp-fnote}.
+% so far, we save the \colorctext{} just with $\Celt^0$ into $\csts$ by
+% \!\pcol@savecolorstack!.  Then we \!\insert! \!\footins! through itself to
+% the main vertical list if it is not $\bot$ and thus has footnotes to be
+% \mgfnote{}.  This \!\insert!ion is different from other footnote
+% \!\insert!ion because \!\footins! is not \!\unvbox!ed but is put as a
+% whole and is followed by \!\penalty!\!\interlinepenalty!, so that
+% footnotes will not be broken by \TeX's page builder to prevent the
+% reconnection of a broken footnote with innapropriate glue discarding,
+% which we will discuss in \secref{sec:imp-fnote}.
 % 

 %    \begin{macrocode}
   \global\pcol@currcol\z@
   \pcol@getcurrcol
-  \gdef\pcol@colorstack{}\pcol@savecolorstack
+  \pcol@savecolorstack
   \@cons\@freelist\@currbox \unvbox\@currbox
   \ifvoid\footins\else
     \pcol@Log\pcol@output@start{insert}\footins
@@ -5427,7 +5659,7 @@
 \def\pcol@makenormalcol#1{%
   \ifvoid\footins \@tempswafalse \else \@tempswatrue \fi
   \ifpcol@mgfnote \ifnum#1=\@ne \@tempswafalse \fi\fi
-  \if@tempswa 
+  \if@tempswa
     \pcol@Log\pcol@makenormalcol{output}\footins
     \pcol@combinefootins\@holdpg\footins
   \else
@@ -5931,49 +6163,355 @@
 % \begin{macro}{\pcol@set@color@push}
 % \changes{v1.2-1}{2013/05/11}
 % 	{Introduced to work as \cs{set@color}.}

-% \begin{macro}{\reset@color}
-% \begin{macro}{\pcol@reset@color}
+% \changes{v1.22}{2013/06/30}
+%	{Modified to push color stack by \cs{output} always.}

 % \begin{macro}{\pcol@reset@color@pop}
 % \changes{v1.2-1}{2013/05/11}
 % 	{Introduced to work as \cs{reset@color}.}

+% \changes{v1.22}{2013/06/30}
+%	{Modified to pop color stack by \cs{output} always.}

+% 

+% The macro \!\pcol@set@color@push! is invoked whenever \LaTeX's
+% counterpart \!\set@color!  appears in a \env{paracol} environment through
+% coloring commands such as \!\color!, because \!\paracol! replaces \LaTeX's
+% macro with it saving the original version in \!\pcol@set@color!, if the
+% origina \!\set@color! is not \!\relax! to mean some coloring package is in
+% use.
+% 
+% The macro at first invokes the original versions of its \LaTeX's
+% counterpart to let it put appropriate coloring \!\special! to |.dvi|.
+% Then, if we are neigher in a \!\vbox! nor in restricted horizontal mode,
+% we push the contents of \!\current@color!, which \!\set@color! should
+% refer to as the color information to be set, into the shadow \colorstack{}
+% $\cstshadow=\!\pcol@colorstack@shadow!$ for the stack rewiding\slash
+% reestablishing in \!\columncolor! and \!\normalcolumncolor!.  Since this
+% push is done non-\!\global!ly with \!\edef!, we save\slash restore the
+% definition of \!\@elt! to\slash from \Midx{\!\pcol@elt@save!} before\slash
+% after the push, resepctively\footnote{

+% 

+% Just in case.}.
+% 

+% The color information is also added to the list
+% $\cstb=\!\pcol@colorstack@buf!$ so that the push to $\cst$ is done in
+% \!\pcol@output@cpush! invoked by the \!\output! request \!\pcol@op@cpush!
+% made by \!\pcol@color@invokeoutput!.
+% 
+% As for the pop, we reserve the invocation of \!\pcol@reset@color@pop! by
+% \!\aftergroup! in \!\pcol@set@color@push! in order to make another
+% \!\output! request \!\pcol@op@cpop! so that the pop operation is done in
+% \!\pcol@output@cpop!.  One caution is that \!\pcol@reset@color@pop! can be
+% invoked outside the \env{paracol} environment in which the corresponding
+% \!\pcol@set@color@push! appears.  In this case with
+% $\CSIndex{ifpcol@output}=\false$, we don't need to do the pop operation
+% and cannot make the \!\output! request for it because \!\output! is not
+% for \env{paracol}.
+% 

+%    \begin{macrocode}
+%% Special Output Routines: Color
+
+\def\pcol@set@color@push{\pcol@set@color
+  \ifmmode\else \ifinner \pcol@innertrue \fi\fi
+  \ifpcol@inner\else
+    \aftergroup\pcol@reset@color@pop
+    \let\pcol@elt@save\@elt \let\@elt\relax
+    \edef\pcol@colorstack@shadow{\pcol@colorstack@shadow\@elt{\current@color}}%
+    \@cons\pcol@colorstack@buf{{\current@color}}%
+    \let\@elt\pcol@elt@save
+    \pcol@color@invokeoutput\pcol@op@cpush
+  \fi}
+\def\pcol@reset@color@pop{\ifpcol@output
+  \pcol@color@invokeoutput\pcol@op@cpop \fi}
+
+%    \end{macrocode}
+% \end{macro}\end{macro}\end{macro}\end{macro}
+% 
+% \begin{macro}{\columncolor}
+% \changes{v1.2-1}{2013/05/11}
+% 	{Introduced to define the default color of a column.}

+% \changes{v1.22}{2013/06/30}
+%	{Add the definition of \cs{pcol@colorcommand} for warning in
+% 	 \cs{pcol@icolumncolor}.}

+% \begin{macro}{\pcol@xcolumncolor}
+% \changes{v1.2-1}{2013/05/11}
+% 	{Introduced to implement \cs{columncolor}.}

+% \begin{macro}{\pcol@ycolumncolor}
+% \changes{v1.2-1}{2013/05/11}
+% 	{Introduced to implement \cs{columncolor}.}

+% \begin{macro}{\pcol@columncolor}
+% \changes{v1.2-1}{2013/05/11}
+% 	{Introduced to implement \cs{columncolor}.}

+% 

+% The API macro \!\columncolor!\oarg{mode}\marg{color}\oarg{c} defines the
+% default color specified by $\arg{color}$ optionally with color
+% $\arg{mode}$ of the column $c$ being the current column or that specified
+% by the optional argument.  After \!\def!ining \Midx{\!\pcol@colorcommand!}
+% being the \!\string! of this macro itself, and processing two optional
+% arguments $\arg{mode}$ and $c$ through macros \!\pcol@xcolumncolor!,
+% \!\pcol@ycolumncolor! and \!\pcol@columncolor!, the macro
+% \!\pcol@icolumncolor!\marg{cmd}\oarg{c} is invoked to perform real
+% operations with the coloring command
+% $\arg{cmd}=\!\color!$\oarg{mode}\marg{color}.
+% 

+%    \begin{macrocode}
+\def\columncolor{\def\pcol@colorcommand{\string\columncolor}%
+  \@ifnextchar[%]
+    \pcol@xcolumncolor\pcol@ycolumncolor}
+\def\pcol@xcolumncolor[#1]#2{\pcol@columncolor{\color[#1]{#2}}}
+\def\pcol@ycolumncolor#1{\pcol@columncolor{\color{#1}}}
+\def\pcol@columncolor#1{\@ifnextchar[%]
+  {\pcol@icolumncolor{#1}}{\pcol@icolumncolor{#1}[\number\pcol@currcol]}}
+%    \end{macrocode}
+% \end{macro}\end{macro}\end{macro}\end{macro}
+% 

+% \begin{macro}{\normalcolumncolor}
+% \changes{v1.2-1}{2013/05/11}
+% 	{Introduced to define the default color of a column is
+%	 \cs{normalcolor}.}
 
+% \changes{v1.22}{2013/06/30}
+%	{Add the definition of \cs{pcol@colorcommand} for warning in
+% 	 \cs{pcol@icolumncolor}.}

+% 

+% The API macro \!\normalcolumncolor!\oarg{c} defines the default color of
+% the column $c$, being the current column or that specified by the optional
+% argument, is \!\normalcolor!.  That is, after \!\def!ining
+% \Midx{\!\pcol@colorcommand!}  being the \!\string! of this macro itself,
+% this macro simply invokes \!\pcol@icolumncolor!\marg{cmd}\oarg{c} to
+% perform real operations with the coloring command
+% $\arg{cmd}=\!\normalcolor!$.
+% 

+%    \begin{macrocode}
+\def\normalcolumncolor{\def\pcol@colorcommand{\string\normalcolumncolor}%
+  \@ifnextchar[%]
+    {\pcol@icolumncolor\normalcolor}%
+    {\pcol@icolumncolor\normalcolor[\number\pcol@currcol]}}
+%    \end{macrocode}
+% \end{macro}
+% 

+% \begin{macro}{\pcol@icolumncolor}
+% \changes{v1.2-1}{2013/05/11}
+% 	{Introduced to implement \cs{columncolor} and
+%	 \cs{normalcolumncolor}.}
 
+% \changes{v1.22}{2013/06/30}
+%	{Add warning of ineffective uses of \cs{columncolor} and
+%	 \cs{normalcolumncolor}, and modify the mechanism to update
+%	 $\gamma_0^c$ and to rewind\slash reestablish color stack.}

+% \begin{macro}{\pcol@iicolumncolor}
+% \changes{v1.22}{2013/06/30}
+%	{Introduced for setting $\gamma_0^c$ and $\hat\gamma_0^c$, and
+%	 pushing $\chi$.}

+% \begin{macro}{\pcol@getshadowcc}
+% \changes{v1.22}{2013/06/30}
+%	{Introduced for setting $\hat\gamma_0^c$ into $\gamma_0^c$ locally.}

+% 

+% The macro \!\pcol@icolumncolor!\marg{cmd}\oarg{c}, invoked from
+% \!\pcol@columncolor! and \!\normal~columncolor!, performs the operations to
+% define the default color of the column $c$ with the coloring command
+% $\arg{cmd}\in\{\!\color!\hbox{\oarg{mode}}\ARg{color},\,\!\normalcolor!\}$
+% as follows.  First we examine if \!\set@color! is not \!\relax! and we are
+% in non-internal vertical or non-restricted horizontal mode and, if not, we
+% complain the command whose name is in \!\pcol@colorcommand! is ineffective
+% by \!\PackageWarning! and do nothing.  Otherwise and if we are not in a
+% \env{paracol} environment, i.e., \!\paracol! is not \!\let!-equal to
+% \!\pcol@paracol!, or if we are in a column $c'\neq c$, we simply invoke
+% \!\pcol@iicolumncolor! to let both $\Celt^c$ and $\Celtshadow^c$ have the
+% color $\gamma$ specified by $\arg{cmd}$, because $\Celt^c$ will not be
+% referred to by \!\output! routine until a \env{paracol} environment starts
+% or \cswitch{} to $c$ is performed.
+% 
+% Otherwise, i.e., if we are in a \env{paracol} environment and in the
+% column $c$, we temporarily let $\cst=\cstshadow$ and
+% $\Celt^c=\Celtshadow^c$, the latter is done by \!\pcol@getshadowcc! by a
+% lengthy sequence for
+% $\!\let!|\pcol@columncolor|{\cdot}c=|\pcol@columncolor@shadow|{\cdot}c$.
+% 

+% \SpecialArrayIndex{c}{\pcol@columncolor}

+% \SpecialArrayIndex{c}{\pcol@columncolor@shadow}

+% 

+% Then we invoke \!\pcol@clearcolorstack! and \!\pcol@restorecolorstack!
+% before and after the operations to define the default color, so that
+% $\Celt^c$ is placed at the bottom of the \colorstack{} of |.dvi|.
+% 
+% The default color definition is done by adding the color $\gamma$ to the
+% tail of $\cstb$ by \!\pcol@iicolumncolor!, and by letting
+% $\Celtshadow^c=\gamma$ also by \!\pcol@iicolumncolor!, before making the
+% \!\output! request \!\pcol@op@cset! for \!\pcol@output@cset! by
+% \!\pcol@color@invokeoutput!.  Note that the \!\output! request is made
+% outside a group in which we rewind and reestablish the \colorstack{} with
+% $\Celtshadow^c$ and $\cstshadow$ because the temporary setting
+% $\Celt^c=\Celtshadow^c=\gamma$ is harmful if it is seen by \!\output!
+% routine for page breaking which can be invoked at the timing of the
+% request of \!\pcol@op@cset! but just prior to the acceptance of it.
+% 
+% The macro $\!\pcol@iicolumncolor!\arg{cmd}\arg{dcs}\arg{scs}$ at first
+% invokes $\arg{cmd}$ to let \!\current@color! have the printer-specific color
+% information $\gamma$ of $\arg{color}$ or what \!\normalcolor!  specifies,
+% temporarily letting \!\set@color! be \!\relax! to let \!\color! or
+% \!\normalcolor! just do the \!\def!inition of \!\current@color!  without
+% putting coloring \!\special!s nor preparing \colorstack{} popping.  Then
+% we \!\xdef!ine $\arg{dcs}$ being $|\pcol@columncolor|{\cdot}c$,
+% $|\pcol@columncolor@shadwo|{\cdot}c$ or \!\pcol@colorstack@buf! to have
+% $\arg{scs}$ being empty or \!\pcol@colorstack@buf! followed by $\gamma$.
+% That is we let $\Celt^c=\gamma$ or $\Celtshadow^c=\gamma$, or add $\gamma$ at
+% the tail of $\cstb$.
+% 

+% \SpecialArrayIndex{c}{\pcol@columncolor}

+% \SpecialArrayIndex{c}{\pcol@columncolor@shadow}

+% 

+%    \begin{macrocode}
+\def\pcol@icolumncolor#1[#2]{%
+  \ifx\set@color\relax
+    \PackageWarning{paracol}{\pcol@colorcommand\space is not effective
+      without some coloring package}%
+  \else\ifpcol@inner
+    \PackageWarning{paracol}{\pcol@colorcommand\space is not effective
+      when not in outer par mode}%
+  \else\ifinner
+    \PackageWarning{paracol}{\pcol@colorcommand\space is not effective
+      when not in outer par mode}%
+  \else
+    \begingroup
+    \let\@elt\relax 
+    \ifx\pcol@paracol\paracol
+      \pcol@iicolumncolor{#1}{pcol@columncolor#2}{}%
+      \pcol@iicolumncolor{#1}{pcol@columncolor@shadow#2}{}%
+    \else\ifnum#2=\pcol@currcol
+      \begingroup
+        \pcol@getshadowcc{#2}\let\pcol@colorstack\pcol@colorstack@shadow
+        \pcol@clearcolorstack
+        \pcol@iicolumncolor{#1}{pcol@colorstack@buf}{\pcol@colorstack@buf}%
+        \pcol@iicolumncolor{#1}{pcol@columncolor@shadow#2}{}%
+        \pcol@getshadowcc{#2}\pcol@restorecolorstack
+      \endgroup
+      \pcol@color@invokeoutput\pcol@op@cset
+    \else
+      \pcol@iicolumncolor{#1}{pcol@columncolor#2}{}%
+      \pcol@iicolumncolor{#1}{pcol@columncolor@shadow#2}{}%
+    \fi\fi
+    \endgroup
+  \fi\fi\fi
+  \ignorespaces}
+\def\pcol@iicolumncolor#1#2#3{\let\set@color\relax #1%
+  \expandafter\xdef\csname#2\endcsname{#3\@elt{\current@color}}}
+\def\pcol@getshadowcc#1{%
+  \expandafter\let\expandafter\reserved@a
+    \csname pcol@columncolor@shadow#1\endcsname
+  \expandafter\let\csname pcol@columncolor#1\endcsname\reserved@a}
+
+%    \end{macrocode}
+% \end{macro}\end{macro}\end{macro}
+% 
+% \begingroup\let\small\footnotesize
+% \begin{macro}{\pcol@color@invokeoutput}
+% \changes{v1.22}{2013/06/30}
+% 	{Introduced for \cs{output} request for coloring.}

+% \begin{macro}{\pcol@color@invokeoutput@v}
+% \changes{v1.22}{2013/06/30}
+% 	{Introduced for \cs{output} request for coloring.}

+% 

+% The macro $\!\pcol@color@invokeoutput!\arg{pen}$ where
+% $\arg{pen}=|\pcol@op@|{\cdot}f$,
+% 

+% \SpecialIndex{\pcol@op@cpush}

+% \SpecialIndex{\pcol@op@cpop}

+% \SpecialIndex{\pcol@op@cset}

+% 

+% invoked from \!\pcol@set@color@push! ($f=|cpush|$),
+% \!\pcol@reset@color@pop! ($f=|cpop|$) and \!\pcol@icolumncolor!
+% ($f=|cset|$), makes an \!\output! request with $\!\penalty!\arg{pen}$.
+% The following sequence to make the request performed by
+% $\!\pcol@color@invokeoutput@v!\arg{pen}$ is exactly same as that in \LaTeX's
+% \!\end@float!; insert a \!\penalty!  of $-10004$ to save the main vertical
+% list in \!\@holdpg!; save \!\prevdepth!; insert a \!\vbox! to make it sure
+% the following \!\penalty!  of $\arg{pen}$ is kept even when we are at the
+% top of a page; and finally restore \!\prevdepth!.  The sequence is simply
+% excueted when we are in vertical mode, while it is enclosed in \!\vadjust!
+% otherwise.  In addition, when we are in horizotal mode, the \!\vadjust! is
+% followed by a null \!\hskip! which makes it possible that the word
+% following it hyphenated.
+% \end{macro}\end{macro}\endgroup
+% 

+%    \begin{macrocode}
+\def\pcol@color@invokeoutput#1{%
+  \ifvmode \pcol@color@invokeoutput@v{#1}
+  \else \vadjust{\pcol@color@invokeoutput@v{#1}}\ifhmode \hskip\z@ \fi
+  \fi}
+\def\pcol@color@invokeoutput@v#1{\penalty-\@Miv \@tempdima\prevdepth
+  \vbox{}\prevdepth\@tempdima \penalty#1\relax}
+
+%    \end{macrocode}
+% 
+% \begin{macro}{\pcol@output@cpush}
+% \changes{v1.22}{2013/06/30}
+% 	{Introduced for color stack pushing.}

+% \begin{macro}{\pcol@output@icpush}
+% \changes{v1.22}{2013/06/30}
+% 	{Introduced to implement \cs{pcol@output@cpush}.}

+% \begin{macro}{\pcol@output@cpop}
+% \changes{v1.22}{2013/06/30}
+% 	{Introduced for color stack popping.}

 % \begin{macro}{\pcol@reset@color@elt}
 % \changes{v1.2-1}{2013/05/11}
 % 	{Introduced to implement \cs{pcol@reset@color@pop}.}

+% \changes{v1.22}{2013/06/30}
+% 	{Moved from the position where \cs{pcol@reset@color@pop} is defined
+%	 because it is now used only by \cs{pcol@output@cpop}.}

+% \begin{macro}{\pcol@output@cset}
+% \changes{v1.22}{2013/06/30}
+% 	{Introduced to set $\gamma_0^c$.}

+% \begin{macro}{\pcol@output@icset}
+% \changes{v1.22}{2013/06/30}
+% 	{Introduced to implement \cs{pcol@output@cset}.}

+% \begin{macro}{\pcol@return@from@color}
+% \changes{v1.22}{2013/06/30}
+% 	{Introduced to implement \cs{pcol@output@cpush},
+%	 \cs{pcol@output@cpop} and \cs{pcol@output@cset}.}

+% 

+% The macros \!\pcol@output@cpush!, \!\pcol@output@cpop! and
+% \!\pcol@output@cset! are invoked solely from \!\pcol@specialoutput! to
+% process the \!\output! requests \!\pcol@op@cpush! to push \colorstack{},
+% \!\pcol@op@cpop! to pop it, and \!\pcol@op@cset! to set $\Celt^c$
+% respectively.  The macro \!\pcol@output@cpush! removes the first element
+% from $\cstb$ and pushes it into $\cst$ by \!\pcol@output@icpush!.  The macro
+% \!\pcol@output@cpop! pop the stack by \!\pcol@reset@color@pop!, which
+% temporarily makes $\cst$ empty and then scan its copy to add each element
+% to the tail of $\cst$ until the last element is found.  The macro
+% \!\pcol@output@cset! lets $\Celt^c=\cs{pcol@columncolor}{\cdot}c$
 % 

-% The macros \!\pcol@set@color@push! and \!\pcol@reset@color@pop! are
-% invoked whenever \LaTeX's counterparts \!\set@color! and \!\reset@color!
-% appear in a \env{paracol} environment through coloring commands such as
-% \!\color!, because \!\paracol! replaces \LaTeX's macros with them saving
-% the original versions in \!\pcol@set@color! and \!\pcol@reset@color!
-% respectively, if the origina \!\set@color! is not \!\relax! to mean some
-% coloring package is in use.
-% 
-% The macros at first invoke the original versions of their \LaTeX's
-% counterparts to let them put appropriate coloring \!\special! to |.dvi|.
-% Then, \!\pcol@set@color@push! pushes the contents of \!\current@color!,
-% which \!\set@color! should refer to as the color information to be set,
-% into the \colorstack{} $\cst=\!\pcol@colorstack!$, or in other words adds
-% it to the tail of $\cst$ by \!\@cons!.
-% 
-% On the other hand, \!\pcol@reset@color@pop! pops the \colorstack{} $\cst$
-% removing its last element.  The removal is done by applying
-% \!\pcol@reset@color@elt! to each member of $\cst$ to add it to the new
-% stack, which becomes $\cst$, by \!\@cons! unless it is the tail element.
+% \SpecialArrayIndex{c}{\pcol@columncolor}

+% 

+% have the first element of $\cstb$ by \!\pcol@output@icset!.
+% After that, these macros commonly invoke \!\pcol@return@from@color! to
+% put the contents of \!\@holdpg! back to the main vertical list, to put
+% \!\footins! as well by \!\@reinserts!, and to add a penalty of 10000 or
+% \!\interlinepenalty! acoording to \CSIndex{if@nobreak}, as if the building
+% process of main vertical list is not interrupted.
 % 

 %    \begin{macrocode}
-%% Special Output Routines: Color
-
-\def\pcol@set@color@push{\pcol@set@color
-  \@cons\pcol@colorstack{{\current@color}}}
-\def\pcol@reset@color@pop{\pcol@reset@color \begingroup
+\def\pcol@output@cpush{%
+  \expandafter\pcol@output@icpush\pcol@colorstack@buf\@nil
+  \pcol@return@from@color}
+\def\pcol@output@icpush\@elt#1#2\@nil{%
+  \@cons\pcol@colorstack{{#1}}\gdef\pcol@colorstack@buf{#2}}
+\def\pcol@output@cpop{\begingroup
   \let\reserved@a\pcol@colorstack
   \gdef\pcol@colorstack{}\let\@elt\pcol@reset@color@elt
-  \reserved@a\@elt\@nil \endgroup}
+  \reserved@a\@elt\@nil
+  \endgroup
+  \pcol@return@from@color}
 \def\pcol@reset@color@elt#1\@elt#2{\def\reserved@b{#2}%
   \ifx\reserved@b\@nnil \let\reserved@b\relax
   \else \@cons\pcol@colorstack{{#1}}\def\reserved@b{\@elt{#2}}%
   \fi
   \reserved@b}
+\def\pcol@output@cset{%
+  \expandafter\pcol@output@icset\pcol@colorstack@buf\@nil
+  \pcol@return@from@color}
+\def\pcol@output@icset\@elt#1#2\@nil{{\let\@elt\relax
+  \expandafter\xdef\csname pcol@columncolor\number\pcol@currcol\endcsname{%
+    \@elt{#1}}%
+  \gdef\pcol@colorstack@buf{#2}}}
+\def\pcol@return@from@color{\unvbox\@holdpg \@reinserts
+  \if@nobreak\nobreak \else\addpenalty\interlinepenalty \fi}
 
 %    \end{macrocode}
 % \end{macro}\end{macro}\end{macro}\end{macro}\end{macro}\end{macro}\end{macro}
@@ -5988,16 +6526,15 @@
 % The macro $\!\pcol@ifempty!\arg{box}\arg{then}\arg{else}$ is used in
 % \!\pcol@clearcst@unvbox!, \!\pcol@restorecst@restart! and
 % \!\pcol@measurecolumn! to examine if $\arg{box}$ is empty, and to perform
-% $\arg{then}$ if so or $\arg{else}$ otherwise.
-% Since \TeX{} does not provide any convenient way for examination
-% unfortunately, we perform a series of tricky operations to put the
-% followings into \!\@tempboxa!; a penalty of $\!\pcol@magicpenalty!=12345$
-% whose existence in the $\arg{box}$ is (almost) impossible; contents of
-% $\arg{box}$ put by \!\unvcopy!; and then a \!\global! \!\def!inition of
-% \!\@gtempa! to let it have the decimal representation of \!\lastpenalty!.
-% Since \!\lastpenalty! has $\arg{pen}$ if the last item is
-% $\!\penalty!\arg{pen}$, or 0 otherwise,
-% $\!\@gtempa!=\!\pcol@magicpenalty!$ iff $\arg{box}$ is empty.
+% $\arg{then}$ if so or $\arg{else}$ otherwise.  Since \TeX{} does not
+% provide any convenient way for the examination unfortunately, we perform a
+% series of tricky operations to put the followings into \!\@tempboxa!; a
+% penalty of $\!\pcol@magicpenalty!=12345$ whose existence in the
+% $\arg{box}$ is (almost) impossible; contents of $\arg{box}$ put by
+% \!\unvcopy!; and then a \!\global! \!\def!inition of \!\@gtempa! to let it
+% have the decimal representation of \!\lastpenalty!.  Since \!\lastpenalty!
+% has $\arg{pen}$ if the last item is $\!\penalty!\arg{pen}$, or 0
+% otherwise, $\!\@gtempa!=\!\pcol@magicpenalty!$ iff $\arg{box}$ is empty.
 % 

 %    \begin{macrocode}
 \def\pcol@magicpenalty{12345}
@@ -6028,7 +6565,7 @@
 % the \colorstack{} of |.dvi| saved in $\csts=\!\pcol@colorstack@saved!$ by
 % \!\pcol@restorecst! as the opening \colorctext{} of the \colpage{}.  The
 % stack $\csts$, however, can be empty if $\arg{box}$ already has the
-% \!\special!s, i.e., when we visited of the \colpage{} it had already had
+% \!\special!s, i.e., when we visited the \colpage{} it had already had
 % some items.  Below $\arg{box}$, on the other hand, we put uncoloring
 % \!\special!s by \!\pcol@clearcolorstack! to rewind $\CST^c$ to clear the
 % \colorctext{} of the \colpage{} in |.dvi| temporarily so that afterward it
@@ -6036,22 +6573,22 @@
 % 
 % The macro \!\pcol@clearcolorstack!, also used in \!\pcol@icolumncolor!,
 % simply scans the \colorstack{} $\CST^c$ for the current column $c$, to
-% which \!\pcol@colorstack@full!  is expanded, applying \!\pcol@reset@color!
-% being the original version of \!\reset@color! to each element in it.  That
-% is, we invoke \!\pcol@reset@color! $\Abs{\CST^c}$ times ignoring the color
-% information in each element and the order of elements, expecting
-% \!\reset@color! just pops printer's \colorstack{} or lets printer's text
-% color be \!\current@color!, as defined in all printer |.def|inition files
-% in \textsf{graphic} package.  If the former is chosen for a printer, its
-% \colorstack{} is rewineded as we intend.  Otherwise, the sequence of
-% \!\reset@color! is meaningless but harmless at the same time.
+% which \!\pcol@colorstack@full!  is expanded, applying \!\reset@color!
+% to each element in it.  That is, we invoke \!\reset@color!  $\Abs{\CST^c}$
+% times ignoring the color information in each element and the order of
+% elements, expecting \!\reset@color! just pops printer's \colorstack{} or
+% lets printer's text color be \!\current@color!, as defined in all printer
+% |.def|inition files in \textsf{graphic} package.  If the former is chosen
+% for a printer, its \colorstack{} is rewineded as we intend.  Otherwise,
+% the sequence of \!\reset@color! is meaningless but harmless at the same
+% time.
 % 

 %    \begin{macrocode}
 \def\pcol@clearcst@unvbox#1{%
   \pcol@ifempty#1\relax
    {\pcol@restorecst\pcol@colorstack@saved
     \unvbox#1\pcol@clearcolorstack}}
-\def\pcol@clearcolorstack{{\def\@elt##1{\pcol@reset@color}%
+\def\pcol@clearcolorstack{{\def\@elt##1{\reset@color}%
   \pcol@colorstack@full}}
 
 %    \end{macrocode}
@@ -6150,97 +6687,6 @@
 
 %    \end{macrocode}
 % \end{macro}
-% 
-% \begin{macro}{\columncolor}
-% \changes{v1.2-1}{2013/05/11}
-% 	{Introduced to define the default color of a column.}

-% \begin{macro}{\pcol@xcolumncolor}
-% \changes{v1.2-1}{2013/05/11}
-% 	{Introduced to implement \cs{columncolor}.}

-% \begin{macro}{\pcol@ycolumncolor}
-% \changes{v1.2-1}{2013/05/11}
-% 	{Introduced to implement \cs{columncolor}.}

-% \begin{macro}{\pcol@columncolor}
-% \changes{v1.2-1}{2013/05/11}
-% 	{Introduced to implement \cs{columncolor}.}

-% 

-% The API macro \!\columncolor!\oarg{mode}\marg{color}\oarg{c} defines the
-% default color specified by $\arg{color}$ optionally with color
-% $\arg{mode}$ of the column $c$ being the current column or that specified
-% by the optional argument.  Via macros \!\pcol@xcolumncolor!,
-% \!\pcol@ycolumncolor! and \!\pcol@columncolor! to process two optional
-% arguments $\arg{mode}$ and $c$, the macro
-% \!\pcol@icolumncolor!\marg{cmd}\oarg{c} is invoked to perform real
-% operations with the coloring command
-% $\arg{cmd}=\!\color!$\oarg{mode}\marg{color}.
-% 

-%    \begin{macrocode}
-\def\columncolor{\@ifnextchar[%]
-  \pcol@xcolumncolor\pcol@ycolumncolor}
-\def\pcol@xcolumncolor[#1]#2{\pcol@columncolor{\color[#1]{#2}}}
-\def\pcol@ycolumncolor#1{\pcol@columncolor{\color{#1}}}
-\def\pcol@columncolor#1{\@ifnextchar[%]
-  {\pcol@icolumncolor{#1}}{\pcol@icolumncolor{#1}[\number\pcol@currcol]}}
-%    \end{macrocode}
-% \end{macro}\end{macro}\end{macro}\end{macro}
-% 

-% \begin{macro}{\normalcolumncolor}
-% \changes{v1.2-1}{2013/05/11}
-% 	{Introduced to define the default color of a column is
-%	 \cs{normalcolor}.}
 
-% 

-% The API macro \!\normalcolumncolor!\oarg{c} defines the default
-% color of the column $c$, being the current column or that specified
-% by the optional argument, is \!\normalcolor!.  That is, this macro simply
-% invokes \!\pcol@icolumncolor!\marg{cmd}\oarg{c} to perform real
-% operations with the coloring command $\arg{cmd}=\!\normalcolor!$.
-% 

-%    \begin{macrocode}
-\def\normalcolumncolor{\@ifnextchar[%]
-  {\pcol@icolumncolor\normalcolor}%
-  {\pcol@icolumncolor\normalcolor[\number\pcol@currcol]}}
-%    \end{macrocode}
-% \end{macro}
-% 

-% \begin{macro}{\pcol@icolumncolor}
-% \changes{v1.2-1}{2013/05/11}
-% 	{Introduced to implement \cs{columncolor} and
-%	 \cs{normalcolumncolor}.}
 
-% 

-% The macro \!\pcol@icolumncolor!\marg{cmd}\oarg{c}, invoked from
-% \!\pcol@columncolor! and \!\normal~columncolor!, performs the operations to
-% define the default color of the column $c$ with the coloring command
-% $\arg{cmd}\in\{\!\color!|[|\arg{mode}|]|\ARg{color},\,\!\normalcolor!\}$
-% as follows if \!\set@color! is not \!\relax!.  First, we invoke
-% $\arg{cmd}$ to let \!\current@color! have the printer-specific color
-% information $\celt$ of $\arg{color}$ or what \!\normalcolor!  specifies,
-% temporarily letting \!\set@color! be \!\relax! to let \!\color!  or
-% \!\normalcolor!  just do the \!\def!inition of \!\current@color!  without
-% putting coloring \!\special!s nor preparing \colorstack{} popping.  Then
-% we \!\xdef!ine $|\pcol@columncolor|{\cdot}c$ to have $\celt$, i.e., we let
-% $\Celt^c=\celt$.
-% 

-% \SpecialArrayMainIndex{c}{\pcol@columncolor}
-% 

-% Note that these operations are surrounded by \!\pcol@clearcolorstack! and
-% \!\pcol@restorecolorstack! if we are in \env{paracol} enviroment, i.e.,
-% \!\paracol! is not \!\pcol@paracol!, so that $\Celt^c$ sits at the bottom
-% of \colorstack{} $\CST^c$ of |.dvi|.
-% 

-%    \begin{macrocode}
-\def\pcol@icolumncolor#1[#2]{%
-  \ifx\set@color\relax\else
-    \ifx\pcol@paracol\paracol\else \pcol@clearcolorstack \fi
-    \begingroup
-    \let\@elt\relax \let\set@color\relax #1%
-    \expandafter\xdef\csname pcol@columncolor#2\endcsname
-      {\@elt{\current@color}}%
-    \endgroup
-    \ifx\pcol@paracol\paracol\else \pcol@restorecolorstack \fi
-  \fi}
-
-%    \end{macrocode}
-% \end{macro}
 % 
 % 
 % 
@@ -6713,6 +7159,8 @@
 % \changes{v1.2-7}{2013/05/11}
 % 	{Replace \cs{@makecol} with \cs{pcol@@makecol} to cap the depth of
 %	 \cs{@outputbox} by \cs{@maxdepth} even with p\string\LaTeX.}
+% \changes{v1.21}{2013/06/06}
+%	{Add page and column numbers to logging.}

 % 

 % The macro \!\pcol@flushcolumn! is invoked for each column $c\In0\C$ from
 % \!\pcol@sync! to ship out the \ccolpage{} of $c$ into $\S_c$ if it is not
@@ -6800,7 +7248,7 @@
       \pcol@shrinkcolbyfn\pcol@footins
       \setbox\@cclv\vbox{\pcol@unvbox@cclv\pcol@footins}%
     \fi
-    \pcol@Logstart\pcol@flushcolumn
+    \pcol@Logstart{\pcol@flushcolumn(\number\c@page:\number\pcol@currcol)}
     \ifdim\@toproom=\maxdimen
       \setbox\@outputbox\pcol@makefcolpage \global\@toproom\z@
     \else
@@ -6874,6 +7322,10 @@
 % \changes{v1.2-7}{2013/05/11}
 % 	{Add the restore of \cs{ifpcol@lastpage} from
 %	 \cs{ifpcol@lastpagesave}.}

+% \changes{v1.21}{2013/06/06}
+%	{Fix the bug that $\kappa_c(\beta^p)$ is let have \cs{pcol@page},
+%        which can be less than $p_t\EQ\cs{pcol@toppage}$, to cause the column
+%	 $c$ is lost or moved to a wrong page.}

 % 

 %    \begin{macrocode}
     \ifpcol@lastpagesave \pcol@lastpagetrue \fi
@@ -6889,7 +7341,7 @@
         \pcol@trynextcolumn
     \fi\fi
     \pcol@setcurrcolnf
-    \global\count\@currbox\pcol@page
+    \global\count\@currbox\pcol@toppage
     \advance\@pageht-\@colht \advance\@pageht\@colroom
     \global\dimen\@currbox\@pageht
   \fi %\ifnum\count\@currbox<\pcol@toppage
@@ -7091,7 +7543,7 @@
 % 

 %    \begin{macrocode}
   \pcol@ifempty\@currbox
-   {\global\pcol@prevdepth\maxdimen \pcol@setcurrcol}% 
+   {\global\pcol@prevdepth\maxdimen \pcol@setcurrcol}%
    {\@tempswatrue}%
   \pcol@measureupdate\@tempdima\dimen@ii\@tempdimc\pcol@prevdepth
 %    \end{macrocode}
@@ -8120,6 +8572,8 @@
 % \changes{v1.2-5}{2013/05/11}
 %	{Move the setting of \cs{linewidth} and \cs{hsize} from
 %	 \cs{pcol@getcurrcol} to this macro and add \cs{parshape}.}

+% \changes{v1.21}{2013/06/06}
+%	{Add zero-clearing of \cs{deadcycles}.}
 % 

 % Before giving the definition of \env{paracol} environment and commands
 % used in it, we define the macro $\!\pcol@invokeoutput!\arg{pen}$ invoked
@@ -8131,10 +8585,12 @@
 % of $\arg{pen}$ is kept even when we are at the top of a page; and finally
 % restore \!\prevdepth!.
 % 
-% The difference is in the save\slash restore of \!\prevdepth!.  First, the
-% value of the register is saved in our own \!\pcol@prevdepth! instead of
-% \!\@tempdima! by a \!\global! assignment so that \!\output!-routine refers
-% to it\footnote{

+% A difference is that we zero-clear \!\deadcycles! because it can be reach
+% $\!\maxdeadcycles!=100$ easily if a page has many \sync{}ations and many
+% columns.  Another and more important difference is in the save\slash
+% restore of \!\prevdepth!.  First, the value of the register is saved in
+% our own \!\pcol@prevdepth! instead of \!\@tempdima! by a \!\global!
+% assignment so that \!\output!-routine refers to it\footnote{

 % 

 % The assignment is not necessary to be done \!\global!ly but we dare to do
 % it to make all assignments to \!\pcol@prevdepth! being \!\global!
@@ -8171,7 +8627,7 @@
 %    \begin{macrocode}
 %% Starting Environment
 
-\def\pcol@invokeoutput#1{%
+\def\pcol@invokeoutput#1{\deadcycles\z@
   \pcol@Logstart{\pcol@invokeoutput
     {#1:\the\pcol@currcol/\the\pcol@nextcol%
      \ifnum#1=-10011:\ifpcol@sync s\fi \ifpcol@clear c\fi\fi}}%
@@ -8338,20 +8794,69 @@
   \let\pcol@@combinefloats\@combinefloats \let\@combinefloats\pcol@combinefloats
 %    \end{macrocode}
 % 

-% Next, we redefine \LaTeX's \!\set@color! and \!\reset@color!, after saving
-% their original definitions in \!\pcol@set@color! and \!\pcol@reset@color!,
-% so that they work as \!\pcol@set@color@push! and \!\pcol@reset@color@pop!
-% with \colorstack, if $\!\set@color!\neq\!\relax!$ meaning some coloring
-% package is loaded.
+% Next, we redefine \LaTeX's \!\set@color!, after saving its original
+% definition in \!\pcol@set@color!, so that it works as
+% \!\pcol@set@color@push!  with \colorstack, if $\!\set@color!\neq\!\relax!$
+% meaning some coloring package is loaded.
+% 
+% If the coloring is enabled, we also prepare the mechanism to let
+% $\CSIndex{ifpcol@inner}=\true$ in every \!\vbox! in the \env{paracol}
+% environment as follows.  First, we let $\CSIndex{ifpcol@inner}=\false$
+% because we are not in any \!\vbox!es obviously.  Then, to use
+% \!\everyvbox! for our own pupose, we do the followings; (1) \!\global!ly
+% assign a token \Midx{\!\pcol@dummytoken!}, which should never occurs, to
+% \!\pcol@everyvbox!; (2) save \!\everyvbox! into \!\pcol@everyvbox!
+% locally; (3) let it have a \!\the!-reference to \!\pcol@everyvbox! and
+% |\pcol@innerture| to let $\CSIndex{ifpcol@inner}={\true}$; and then (4)
+% make \!\everyvbox! \!\let!-equal to \!\pcol@everyvbox!.  By the last
+% operation (4), any \!\everyvbox! appearing in the \env{paracol}
+% environment is replaced with \!\pcol@everyvbox! to keep the real
+% \!\everyvbox! from modified nullifying our own |\pcol@innertrue|.  On the
+% other hand, since both \!\everyvbox! and \!\pcol@everyvbox! are registers
+% to hold tokens and thus any operations applicable to \!\everyvbox! are
+% also applicable to \!\pcol@everyvbox!, any updates on \!\everyvbox! and
+% explicit references to it are simulated by \!\pcol@everyvbox!.  Then the
+% initial tokens given to \!\pcol@everyvbox!  by the saving operation (2) or
+% tokens given inside the environment are correctly processed whenever a
+% \!\vbox! is opened, toghether with |\pcol@innertrue| to fulfill our own
+% purpose, because the real \!\everyvbox! is let have a \!\the!-reference to
+% \!\pcol@everyvbox! by (3).  We also reserve the invocation of
+% \!\pcol@restoreeveryvbox! by \!\aftergroup! so that the macro is invoked
+% just after \Endparacol{} to examine if any \!\global! assignments to
+% \!\everyvbox! has been made in the environment.  The funny \!\global!
+% assignment (1) is done for this examination so that we detect global
+% assignments done in the environment having been closed because they should
+% have changed the global value of \!\pcol@everyvbox! to something different
+% from \!\pcol@dummytoken!.
+% 
+% Finally we empty \colorstack{}s $\cst=\!\pcol@colorstack!$ and
+% $\cstshadow={}$\!\pcol@colorstack@shadow! and the pushing list
+% $\cstb=\!\pcol@colorstack@buf!$ to give them initial states.
 % 

 % \changes{v1.2-1}{2013/05/11}
 % 	{Add redefinitions of \cs{set@color} and \cs{reset@color}.}

+% \changes{v1.22}{2013/06/30}
+% 	{Add a trick with \cs{everyvbox} to turn on \cs{ifpcol@inner} in
+%	 every \cs{vbox}.}

+% \changes{v1.22}{2013/06/30}
+% 	{Move initial emptying of $\string\mathit{\Gamma}$ from
+%	 \cs{pcol@output@start} to \cs{paracol}.}

+% \changes{v1.22}{2013/06/30}
+% 	{Add initial emptying of $\string\hat{\mathit{\Gamma}}$ and $\chi$.}

 % 

 %    \begin{macrocode}
-  \let\pcol@set@color\set@color \let\pcol@reset@color\reset@color 
+  \let\pcol@set@color\set@color
   \ifx\set@color\relax\else
-    \let\set@color\pcol@set@color@push \let\reset@color\pcol@reset@color@pop
+    \let\set@color\pcol@set@color@push
+    \pcol@innerfalse
+    \global\pcol@everyvbox{\pcol@dummytoken}%
+    \pcol@everyvbox\everyvbox
+    \everyvbox{\the\pcol@everyvbox \pcol@innertrue}
+    \let\everyvbox\pcol@everyvbox
+    \aftergroup\pcol@restoreeveryvbox
   \fi
+  \gdef\pcol@colorstack{}%
+  \gdef\pcol@colorstack@buf{}\gdef\pcol@colorstack@shadow{}%
 %    \end{macrocode}
 % 

 % \changes{v1.2-2}{2013/05/11}
@@ -8649,7 +9154,7 @@
 % assignments to it.
 % 

 %    \begin{macrocode}
-%% Counter Opearations
+%% Counter Operations
 
 \def\globalcounter#1{{%
   \@tempswafalse \def\reserved@a{#1}%
@@ -10327,6 +10832,34 @@
     \global\c@footnote\pcol@footnotebase
     \global\advance\c@footnote\pcol@nfootnotes
   \fi}
+
+%    \end{macrocode}
+% \end{macro}
+% 
+% \begin{macro}{\pcol@restoreeveryvbox}
+% \changes{v1.22}{2013/06/30}
+% 	{Introduced to reflect \cs{global} updates on \cs{everyvbox} in
+%	 \string\texttt{paracol} environments.}
+% 

+% The macro \!\pcol@restoreeveryvbox! is invoked just after \Endparacol{} by
+% \!\aftergroup! mechanism activated by \!\paracol!.  It examines if
+% \!\pcol@everyvbox! has tokens different from \!\pcol@dummytoken! which
+% \!\paracol! \!\global!ly assigned to the register.  Since the dummy token
+% cannot be assigned to \!\everyvbox!\footnote{

+% 

+% Unless a very surprising coincidence happens or a user intentionally
+% violates the coherence of the implementation.},
+% 

+% the difference means the \!\everyvbox! has been \!\global!ly updated with
+% the value that \!\pcol@everyvbox! has now.  Therefore if so, we
+% globally update \!\everyvbox! with \!\pcol@everyvbox! to refrect the
+% global update in the environment.
+% 

+%    \begin{macrocode}
+\def\pcol@restoreeveryvbox{%
+  \expandafter\def\expandafter\reserved@a\expandafter{\the\pcol@everyvbox}%
+  \def\reserved@b{\pcol@dummytoken}%
+  \ifx\reserved@a\reserved@b\else \global\everyvbox\pcol@everyvbox \fi}
 %    \end{macrocode}
 % \end{macro}
 %\iffalse
diff --git a/Master/texmf-dist/source/latex/paracol/man.dtx b/Master/texmf-dist/source/latex/paracol/man.dtx
index fc6486a14fe..15a478b03ba 100644
--- a/Master/texmf-dist/source/latex/paracol/man.dtx
+++ b/Master/texmf-dist/source/latex/paracol/man.dtx
@@ -9,7 +9,7 @@
 % Suppose you are writing a bilingual document whose left column is written in
 % a language, say English, and right column has the translation of the left
 % column in another language, e.g. Japanese.  With the \textsf{paracol}
-% package you may write an English part of arbitrary length and then {\em
+% package you may write an English part of arbitrarily length and then {\em
 % switch} to its Japanese counterpart to place both parts side by side.  Of
 % course you may return to the English writing similarly.
 % 
@@ -213,7 +213,7 @@
 % \subsection{Environment \texttt{column}}
 % The \!\switchcolumn! is simple but you may prefer to pack the contents of a
 % column in an environment.  The \Uidx{\env{column}} environment is
-% available for this well-structurization of \LaTeX{} sources for
+% available for this well-structuralization of \LaTeX{} sources for
 % parallel-columned documents. A construct;
 % \begin{quote}
 % \!\begin!|{|\env{column}|}|\\
@@ -684,7 +684,7 @@
 % \changes{v1.1}{2012/05/11}
 % 	{Add \cs{columnratio}\texttt{\char`\{0.6\char`\}} and a phrase
 %	 for it.}
-% Now the aurthor will do |\flushpage| shortly to start a real binlingual
+% Now the author will do |\flushpage| shortly to start a real binlingual
 % example from the next page, after showing another example of closing 
 % \env{paracol} environment in this sentence and of restarting in the next
 % one, in which {\em unbalanced column width} is demonstrated using
@@ -737,8 +737,10 @@
 % \begin{Gverse}
 % \itshape O Freunde, nicht diese T\"one! \\
 % Sondern la{\ss}t uns angenehmere anstimmen und freu\-denvollere

-% \footnote{If I had been a good student in my German class, this footnote
-% would say ``This part was added by Beethoven.'' in German.}.
+% \footnote{If I had been a good student in my German class, I could find
+% the German translation of the right column footnote \ref{fn:right4} is
+% ``Dieser Teil wurde von Beethoven hinzugef\"ugt'' by myself without
+% the kind help from a user.}
 % \end{Gverse}
 % \begin{Everse}
 % \itshape Oh friends, no more of these sad tones!\\
diff --git a/Master/texmf-dist/source/latex/paracol/paracol.dtx b/Master/texmf-dist/source/latex/paracol/paracol.dtx
index 7bf88f8847f..e7039219dcb 100644
--- a/Master/texmf-dist/source/latex/paracol/paracol.dtx
+++ b/Master/texmf-dist/source/latex/paracol/paracol.dtx
@@ -2,7 +2,7 @@
 %<paracol>%% Style file `paracol'.
 %<man>%% LaTeX file 'paracol-man'.
 %<*paracol|man>
-%% Copyright (C) 2005-2012
+%% Copyright (C) 2005-2013
 %%   Hiroshi Nakashima <h.nakashima@DOMAIN;  DOMAIN=media.kyoto-u.ac.jp>
 %%   (Kyoto University)
 %% This program can be redistributed and/or modified under the terms
@@ -19,13 +19,13 @@
 %<man>\ProvidesFile{paracol-man.tex}
 % \fi
 % \ProvidesFile{paracol.dtx}
-[2013/05/11 v1.2 ]
+[2013/06/30 v1.22 ]
 % \iffalse
 %<*man>
 \documentclass{ltxdoc}
+\usepackage{color}
 \usepackage{paracol}
 \usepackage{newvbtm}
-\usepackage{color}
 \DisableCrossrefs
 \PageIndex
 \CodelineNumbered
@@ -413,10 +413,12 @@
 % \def\vb{\Index[$\kappa_c(\beta)$]{-k_c(-b)}\beta}
 % \def\pd{\Index[$\kappa_c(\delta)$]{-k_c(-d)}\delta}
 % \def\Celt{\Index[$\gamma_0^c$]{-c_0^c}\gamma_0}
+% \def\Celtshadow{\Index[$\hat\gamma_0^c$]{-c_0^c'}\hat\gamma_0}
 % \def\celt{\Index[$\gamma_i$]{-c_i}\gamma}
 % \def\cst{\Index[$\string\mathit{\Gamma}$]{-C}\mathit{\Gamma}}
 % \def\CST{\Index[$\string\mathit{\Gamma}^c$]{-C^c}\mathit{\Gamma}}
 % \def\csts{\Index[$\string\mathit{\Gamma_s}$]{-C_s}\mathit{\Gamma}_s}
+% \def\cstshadow{\Index[$\hat\string\mathit{\Gamma}$]{-C'}\hat\mathit{\Gamma}}
 % \def\ep{\Index[$\kappa_c(\varepsilon)$]{-k_c(-e)}\varepsilon}
 % \def\clist{\Index[$\zeta(\theta)$]{-f(-j)}\zeta}
 % \def\fh{\Index[$\kappa_c(\eta)$]{-k_c(-h)}\eta}
@@ -445,6 +447,7 @@
 % \def\sw{\Index[$\kappa_c(\sigma)$]{-k_c(-s)}\sigma}
 % \def\ft{\Index[$\kappa_c(\tau)$]{-k_c(-t)}\tau}
 % \def\df{\Index[$\string\mathit{\Phi}$]{-U}\mathit{\Phi}}
+% \def\cstb{\Index[$\chi$]{-x}\chi}
 % 
 % \def\bf{\Index[$b_f$]{b_f}b_f}
 % \def\C{\Index[$C$]{C}C}
@@ -536,6 +539,12 @@
 %	{Add \cs{localcounter}.}
 % \changes{v1.2-7}{2013/05/11}
 %	{Bug fixes and minor revisions as follows.}
+% \changes{v1.21}{2013/06/06}
+%	{Fix the bug by which a column having empty column-pages followed by
+%	 a synchronization point is lost or placed in a wrong page.}
+% \changes{v1.22}{2013/06/30}
+%	{Fix the bug \cs{color} and its relatives in a paragraph or around
+%	 page top causes inconsistency of color context.}
 %
 % 
 % 
@@ -548,6 +557,7 @@
 % \setbox0\vbox{\vskip\topskip\maketitle\vskip0pt}\unitlength\ht0\copy0
 % 
 % \ifx\ONLYDESCRIPTION\undefined
+% \vspace*{-4ex}
 % \tableofcontents
 % \newpage
 % 
\vbox to\unitlength{\unvbox0\vfil}
@@ -588,8 +598,14 @@
 % Blas who motivated the author to challenge single-columned footnotes;
 % Olivier Vogel who pointed out the compatibility problem with coloring
 % packages; Heiner Richter who asked for the possibility of swapping
-% unbalanced columns; and an anonymous user who reported a very rare-case
-% but severe bug in the version~1.1 by which a page can be lost (woops!).
+% unbalanced columns; an anonymous user who reported a very rare-case but
+% severe bug in the version~1.1 by which a page can be lost (whoops!);
+% Olivier Gerard who found another terrible bug fixed in version 1.21 but
+% hidden in \textsf{paracol} for two years by which a column disappears or
+% moves to a wrong page (another whoops!) and kindly proofread this manual;
+% and George Kamel who let the auhtor know the coloring function newborn in
+% version 1.2 had a bug fixed in version 1.22 to which he also made a great
+% contribution testing many tentative versions with his own colored documents.
 % 
 % For the implementation of the style file, the author referred to the base
 % implementations of \texttt{\char`\\output}, \texttt{\char`\\newcounter}
diff --git a/Master/texmf-dist/source/latex/paracol/ref.dtx b/Master/texmf-dist/source/latex/paracol/ref.dtx
index d5e29741d5a..bf26658fb3f 100644
--- a/Master/texmf-dist/source/latex/paracol/ref.dtx
+++ b/Master/texmf-dist/source/latex/paracol/ref.dtx
@@ -190,13 +190,12 @@
 % \item
 % In a page having one or more \sync{}ation points, stretch and shrink
 % factors of all vertical spaces, such as those surrounding sectionning
-% commands, are ingonred.  Therefore, even if you specify \!\flushbottom!,
+% commands, are ignored.  Therefore, even if you specify \!\flushbottom!,
 % the page is typeset as if \!\raggedbottom! were specified.
 % 
 % \item
-% After a \sync{}ation point is set, top floats will not be put in the page
-% having the point any more and thus will be deferred to the next or
-% a succeeding page.
+% After a \sync{}ation point is set, no top floats will be inserted in the page
+% having the point, thus they will be deferred to the next page or further one.
 % \end{itemize}
 % 
 % 
@@ -456,7 +455,7 @@
 % Coloring with \!\color!\oarg{mode}\marg{color} and other coloring commands
 % in \env{paracol} environments is of course allowed.  One caution is that
 % the \!\color! decides the color for following texts until other
-% specificatoin is given or the group surrounding the command is closed.
+% specification is given or the group surrounding the command is closed.
 % Therefore, \!\switchcolumn! does not affect the coloring but a color given
 % to the texts in a column is also applied to the texts in the column to be
 % switched to.  This irrelativeness of coloring and \cswitch{} is shown in
@@ -498,7 +497,7 @@
 % \env{paracol} environment of course, and thus this sentence is not
 % colored\footnote{

 % 

-% Or colred black as \cs{normalcolor} specifies.}.
+% Or colored black as \cs{normalcolor} specifies.}.
 % \end{itemize}
 % \end{description}
 % 
diff --git a/Master/texmf-dist/source/latex/paracol/scfnote.dtx b/Master/texmf-dist/source/latex/paracol/scfnote.dtx
index df09316f43c..a1f2a7d692d 100644
--- a/Master/texmf-dist/source/latex/paracol/scfnote.dtx
+++ b/Master/texmf-dist/source/latex/paracol/scfnote.dtx
@@ -50,8 +50,8 @@
 % |\end{paracol}|
 % \end{quote}\vskip-1pt
 % 

-% The real life is, however, togher than that with the too optimistic
-% assumptions above, as described in the following subsections.
+% The real life is, however, tougher than.  The asumptions above are too
+% optimistic as described in the following subsections.
 % \vskip-3pt\vskip0pt
 % 
 % 
@@ -102,7 +102,7 @@
 % impossible, some day you could have an improved version of
 % \textsf{paracol} with the automatic ordering.},
 % 

-% you have to maitain it by yourself.
+% you have to maintain it by yourself.
 % 
 % The problem is partly solved by using \!\footnote! with its optional
 % argument \oarg{num} to number the first right-column and the third
@@ -114,7 +114,7 @@
 % \!\setcounter!|{footnote}{|\texttt{\ref{fn:2L3}}|}| or
 % \!\addtocounter!|{footnote}{2}| after the third left-column footnote.
 % 
-% This remeady, however, cannot change the stacking order of these two
+% This remedy, however, cannot change the stacking order of these two
 % footnotes of cource.  Therefore, you need another trick with
 % \!\footnotemark! and \!\footnotetext! to stack the third left-column
 % footnote above the first right-column one.  More specifically, you can
@@ -195,9 +195,9 @@
 % \item[\Midx{\!\footnote!}\texttt{*}\oarg{|+|disp}\marg{text}]\mbox{}
 % \Item[\Midx{\!\footnote!}\texttt{*}\oarg{|-|disp}\marg{text}]\mbox{}
 % \Item[\Midx{\!\footnote!}\texttt{*}\oarg{disp}\marg{text}]\mbox{}\par
-% The command is similar to its non-starred counterpart but the expicit
+% The command is similar to its non-starred counterpart but the explicit
 % numbering with the optional argument is done in \emph{self-relative} or
-% \emph{base-displacemnt} style.  That is, if the optional argument has a
+% \emph{base-displacement} style.  That is, if the optional argument has a
 % leading `|+|' or `|-|',  the number given to the footnote is
 % $f+\meta{disp}$ or $f-\meta{disp}$ respectively where $f$ is the value of
 % \counter{footnote} counter, or in other words the number given to the last
@@ -265,7 +265,7 @@
 % $\ref{fn:4R1}=\ref{fn:4L0}+4$.\label{fn:4R1}}}{It is followed by a
 % \cs{switchcolumn*}.}
 % \switchcolumn*
-% Third and synchroized left-column paragraph\Dotfill\\
+% Third and synchronized left-column paragraph\Dotfill\\
 % \Dotfill with a footnote whose mark
 % here\footnotemark*[3]\Dotfill\\
 % is given by \!\footnotemark!|*[3]| because $\ref{fn:4L3}=\ref{fn:4L0}+3$.
@@ -305,7 +305,7 @@
 % \counter{footnote} have the value.\label{fn:5R1}}}{It is followed by a
 % \cs{switchcolumn*}.}
 % \switchcolumn*
-% Third and synchroized left-column paragraph\Dotfill\\
+% Third and synchronized left-column paragraph\Dotfill\\
 % \Dotfill with a footnote whose mark
 % here\footnotemark*[-1]\Dotfill\\
 % is given by \!\footnotemark!|*[-1]| because $\ref{fn:5L3}=\ref{fn:5R1}-1$.
@@ -385,7 +385,7 @@
 % this Section~\ref{sec:fnnp}, footnotes are simply numbered in
 % left-column-first manner without any trickes.  However it results in
 % giving an impression that two paragraphs in each of both columns at the
-% bottom of the last page has footnote marks of inconsecutive numbers
+% bottom of the last page have footnote marks of inconsecutive numbers
 % \ref{fn:6L1} and \ref{fn:6R1} due to the second left-column paragraph and
 % the footnote \ref{fn:6L2} in it.  More weirdly, the first right-column
 % footnote \ref{fn:6R1} is not put in the last page where its mark is shown
@@ -612,19 +612,19 @@
 % 	 typesetting issues and warn users of the possiblity of bugs.}

 % 
 % Here a few problems you could face in the use of \textsf{paracol} are
-% summerized.
+% summarized.
 % 

 % \begin{itemize}
 % \item
-% If your (e.g.,) left column goes ahead too farther than the right column,
-% \LaTeX{} could stop with the following error message.
+% If your (e.g.,) left column goes ahead too much farther than the right
+% column, \LaTeX{} could stop with the following error message.
 % 

 % \begin{quote}
 % |! Package paracol Error: Too many unprocessed columns/floats.|
 % \end{quote}
 % 

 % This usually means that the internal space to keep materials in the left
-% column is exhosted.  More specifically, suppose at some point in your
+% column is exhausted.  More specifically, suppose at some point in your
 % |.tex| your left column is in the page $p$ while the right is in $q<p$.
 % We need $(p-q)$ \emph{boxes} to keep the left column contents in the pages
 % $q$, $q+1$, \ldots, $p-1$ because these pages cannot be \emph{printed} yet
@@ -634,9 +634,9 @@
 % least we need to have $(p-q)+2$ boxes, while the number of them provided
 % by \LaTeX{} is only 18\footnote{

 % 

-% Readers who is acquainted with \LaTeX{} implementation will understand
+% Readers who are acquainted with \LaTeX{} implementation will understand
 % that 18 is the cardinarity of the set $\{\cs{bx@A},\ldots,\cs{bx@R}\}$ for
-% floats aquired by \cs{newinsert}.}.
+% floats acquired by \cs{newinsert}.}.
 % 

 % Therefore, \textsf{paracol} cannot continue its work if $(p-q)$ reaches
 % 17.  Furthermore, other stuff also consumes the boxes as follows.
@@ -722,12 +722,13 @@
 % should be, honestly speaking) other unknown problems in \textsf{paracol}
 % because it cannot be perfect though the author has made his best effort
 % for debugging it.  Particulally, sometimes it is very tough, if not
-% impossible, to make \textsf{paracol} combatible with other packages,
+% impossible, to make \textsf{paracol} compatible with other packages,
 % especially with those having dark magic as \textsf{paracol} has in
 % it\footnote{

 % 

 % For example, the author knows it is almost impossible to make
-% \textsf{paracol} with one of the author's own package available in CTAN.}.
+% \textsf{paracol} compatible with one of the author's own package available
+% in CTAN.}.
 % 

 % Therefore, though reporting incompatibleness with a package you use is
 % very welcome\footnote{

@@ -744,13 +745,13 @@
 % 

 % \begin{itemize}
 % \item
-% A page, a column, a footnote and/or a float disappear\footnote{

+% A page, a column, a footnote and/or a float disappears\footnote{

 % 

 % In fact, a bug fixed in version 1.2 caused page losing though it happens
 % very very rarely but an unlucky user encountered it.}.
 % 
 % \item
-% A page, a column, a footnote and/or a float are duplicated.
+% A page, a column, a footnote and/or a float is duplicated.
 % 
 % \item
 % A message like ``{\tt Overfull |\vbox| (1.23456pt too high) has occurred