--- loncom/xml/algebra/AlgParser.pm	2005/02/24 09:06:14	1.9
+++ loncom/xml/algebra/AlgParser.pm	2005/02/24 09:37:05	1.10
@@ -596,7 +596,7 @@ sub tolatex {
       #       added missing trig functions
       #
       #$specialfunc = '(?:abs|logten|asin|acos|atan|sech|sgn|step|fact)';
-      my $specialfunc = '(?:abs|(logten)|a(sin|cos|tan|sec|csc|cot)(h)?|sgn|step|fact)';
+      my $specialfunc = '(?:(logten)|a(sin|cos|tan|sec|csc|cot)(h)?|sgn|step|fact|(abs))';
       #
       #  End DPVC
       #
@@ -608,6 +608,9 @@ sub tolatex {
 	  elsif (defined($2)) {
 	      return ('\mbox{' . $2.$3 .'}^{-1}'. $p1 . $args[1]->tolatex() . $p2);
 	  }
+	  elsif (defined($4)) {
+	      return ('|' . $args[1]->tolatex() . '|');
+	  }
 	  else {
 	      return ('\mbox{' . $args[0] .'}'. $p1 . $args[1]->tolatex() . $p2);
 	  }