--- loncom/xml/algebra/AlgParser.pm	2005/02/24 08:32:11	1.7
+++ loncom/xml/algebra/AlgParser.pm	2005/02/24 08:34:52	1.8
@@ -594,13 +594,21 @@ 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);