--- loncom/xml/algebra/AlgParser.pm	2005/02/24 08:28:43	1.6
+++ loncom/xml/algebra/AlgParser.pm	2005/02/24 08:34:52	1.8
@@ -594,20 +594,30 @@ 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 = '(?:abs|(logten)|a(sin|cos|tan|sec|csc|cot)(h)?|sgn|step|fact)';
       #
       #  End DPVC
       #
 
       if ($args[0] =~ /$specialfunc/) {
-         return ('\mbox{' . $args[0] .'}'. $p1 . $args[1]->tolatex() . $p2);
+	  if (defined($1)) {
+	      return ('\mbox{log}_{10}'. $p1 . $args[1]->tolatex() . $p2);
+	  }
+	  elsif (defined($2)) {
+	      return ('\mbox{' . $2.$3 .'}^{-1}'. $p1 . $args[1]->tolatex() . $p2);
+	  }
+	  else {
+	      return ('\mbox{' . $args[0] .'}'. $p1 . $args[1]->tolatex() . $p2);
+	  }
       }
       else {
         return ('\\' . $args[0] . $p1 . $args[1]->tolatex() . $p2);
       }
   };
   /special/ && do {
-    if ($args[0] eq 'pi') {return '\pi';} else {return $args[0];}
+      if    ($args[0] =~/($greek|$escape)/) {return '\\'.$1;}
+      elsif ($args[0] =~/$delete/) {return '';}
+      else { return $args[0]; }
   };
   /varname|(:?number$)/ && return $args[0];
   /numberE/ && do {