--- loncom/xml/lonxml.pm	2016/08/05 20:57:58	1.531.2.20
+++ loncom/xml/lonxml.pm	2017/12/06 14:23:44	1.531.2.23
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # XML Parser Module 
 #
-# $Id: lonxml.pm,v 1.531.2.20 2016/08/05 20:57:58 raeburn Exp $
+# $Id: lonxml.pm,v 1.531.2.23 2017/12/06 14:23:44 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -69,6 +69,7 @@ use Safe();
 use Safe::Hole();
 use Math::Cephes();
 use Math::Random();
+use Math::Calculus::Expression();
 use Opcode();
 use POSIX qw(strftime);
 use Time::HiRes qw( gettimeofday tv_interval );
@@ -440,9 +441,9 @@ sub latex_special_symbols {
     } else {
 	$string=~s/\\/\\ensuremath{\\backslash}/g;
 	$string=~s/\\\%|\%/\\\%/g;
-	$string=~s/\\{|{/\\{/g;
+	$string=~s/\\\{|{/\\{/g;
 	$string=~s/\\}|}/\\}/g;
-	$string=~s/\\ensuremath\\{\\backslash\\}/\\ensuremath{\\backslash}/g;
+	$string=~s/\\ensuremath\\\{\\backslash\\}/\\ensuremath{\\backslash}/g;
 	$string=~s/\\\$|\$/\\\$/g;
 	$string=~s/\\\_|\_/\\\_/g;
         $string=~s/([^\\]|^)(\~|\^)/$1\\$2\\strut /g;
@@ -914,6 +915,7 @@ sub init_safespace {
   $safehole->wrap(\&Apache::functionplotresponse::fpr_objectcoords,$safeeval,'&fpr_objectcoords');
   $safehole->wrap(\&Apache::functionplotresponse::fpr_vectorlength,$safeeval,'&fpr_vectorlength');
   $safehole->wrap(\&Apache::functionplotresponse::fpr_vectorangle,$safeeval,'&fpr_vectorangle');
+  $safehole->wrap(\&Math::Calculus::Expression::math_calculus_expression,$safeeval,'&math_calculus_expression');
 
 #  use Data::Dumper;
 #  $safehole->wrap(\&Data::Dumper::Dumper,$safeeval,'&LONCAPA_INTERNAL_Dumper');
@@ -1735,11 +1737,11 @@ $initialize
         $xml_help
       </td></tr>
     </table>
-    <div class="LC_edit_problem_discards">
+    <div>
       <input type="submit" name="discardview" accesskey="d" value="$lt{'dv'}" />
       $undo $htmlerror $deps_button $dragmath_button
     </div>
-    <div class="LC_edit_problem_saves">
+    <div style="float:right">
       <input type="submit" name="savethisfile" accesskey="s" value="$lt{'st'}" />
       <input type="submit" name="viewmode" accesskey="v" value="$lt{'vi'}" />
     </div>