1 files changed, 26 insertions, 24 deletions
diff --git a/tex/context/base/thrd-tab.tex b/tex/context/base/thrd-tab.tex
index 8ca90665e..dd3838ce2 100644
--- a/tex/context/base/thrd-tab.tex
+++ b/tex/context/base/thrd-tab.tex
@@ -442,17 +442,17 @@
 
 % DO VCS
 \def\!thDoVCS#1{%
-  \setbox\z@\hbox{#1}%
+  \setbox\zerocount\hbox{#1}%
   \!thFinishVCS}
 
 % DO MATH VCS
 \def\!thDoMathVCS#1#2{%
-  \setbox\z@\hbox{$\m@th#1{#2}$}%
+  \setbox\zerocount\hbox{$\mathsurround\zeropoint#1{#2}$}%
   \!thFinishVCS}
 
 % FINISH VCS
 \def\!thFinishVCS{%
-  \vbox to\z@{\vss\box\z@\vss}}
+  \vbox to\zeropoint{\vss\box\zerocount\vss}}
 
 
 % ***************************************************************
@@ -505,20 +505,20 @@
 
 % DO SIMPLE RAISE
 \def\!thDoSimpleRaise#1{%
-  \setbox\z@\hbox{\raise \!taDimenA\hbox{#1}}%
+  \setbox\zerocount\hbox{\raise \!taDimenA\hbox{#1}}%
   \!thFinishRaise} % From Plain TeX: \ht0=0pt \dp0=0pt \box0
 
 % DO MATH RAISE
 \def\!thDoMathRaise#1#2{%
-  \setbox\z@\hbox{\raise \!taDimenA\hbox{$\m@th#1{#2}$}}%
+  \setbox\zerocount\hbox{\raise \!taDimenA\hbox{$\mathsurround\zeropoint#1{#2}$}}%
   \!thFinishRaise}
 
 % FINISH RAISE. This is the same as Plain's \finsm@sh; some macro
 % packages redefine \finsm@sh.
 \def\!thFinishRaise{%
-  \ht\z@\z@
-  \dp\z@\z@
-  \box\z@}
+  \ht\zerocount\zeropoint
+  \dp\zerocount\zeropoint
+  \box\zerocount}
 
 
 % ***************************************************************
@@ -1481,10 +1481,10 @@
   \ifx\!ttemp\empty
     \!taDimenC=0pt
   \else
-    \setbox0=\hbox{\m@th #1.#3#1}%
+    \setbox0=\hbox{\mathsurround\zeropoint #1.#3#1}%
     \!taDimenC=\wd0
   \fi
-  \setbox0 =\hbox{\m@th #1#2#1}%
+  \setbox0 =\hbox{\mathsurround\zeropoint #1#2#1}%
   \!thToksEdef\!taDataColumnTemplate={%
     \noexpand\!tnSetNumericItem
     {\the\wd0 }%
@@ -1499,11 +1499,11 @@
 
 \def\!tnSetNumericItemA #1#2#3#4.#5.#6!{%
   \def\!ttemp{#6}%
-  \hbox to #1{\hss \m@th #3#4#3}%
+  \hbox to #1{\hss \mathsurround\zeropoint #3#4#3}%
   \hbox to #2{%
     \ifx\!ttemp\empty
     \else
-       \m@th #3.#5#3%
+       \mathsurround\zeropoint #3.#5#3%
     \fi
     \hss}}
 
@@ -1563,25 +1563,25 @@
 
 \def\!TsEnlargeOther#1{%
   \ifhmode
-    \setbox\z@=\hbox{#1%
+    \setbox\zerocount\hbox{#1%
       \xdef\!TsSpaceFactor{\spacefactor=\the\spacefactor}}%
   \else
-    \setbox\z@=\hbox{#1}%
+    \setbox\zerocount\hbox{#1}%
   \fi
   \!TsFinishEnlarge}
 
 \def\!TsEnlargeMath#1#2{%
-  \setbox\z@=\hbox{$\m@th#1{#2}$}%
+  \setbox\zerocount\hbox{$\mathsurround\zeropoint#1{#2}$}%
   \!TsFinishEnlarge}
 
 \def\!TsFinishEnlarge{%
-  \dimen@=\ht\z@
+  \dimen@\ht\zerocount
   \advance \dimen@ \!taDimenA
-  \ht\z@=\dimen@
-  \dimen@=\dp\z@
+  \ht\zerocount\dimen@
+  \dimen@\dp\zerocount
   \advance \dimen@ \!taDimenB
-  \dp\z@=\dimen@
-  \box\z@ \!TsSpaceFactor{}}
+  \dp\zerocount\dimen@
+  \box\zerocount \!TsSpaceFactor{}}
 
 
 % ENLARGE BY MULTIPLES OF StrutUnit
@@ -1883,15 +1883,17 @@
 
 % USE
 % \use <number> spans the next <number> data columns.
+
 \def\!ttuse#1{%
-  \ifnum #1>\@ne
+  \ifnum #1>\plusone
     \omit
     \mscount=#1 %        \mscount is in Plain
-    \advance\mscount by \m@ne
+    \advance\mscount by \minusone
     \advance\mscount by \mscount
     \!thLoop
-      \ifnum\mscount>\@ne
-      \sp@n %            from Plain (\span\omit \advance\mscount\m@ne)
+      \ifnum\mscount>\plusone
+        % \sp@n: from plain
+        \spanomit \advance\mscount\minusone
     \repeat
     \span
   \fi}