--- loncom/homework/lonmaxima.pm	2007/04/19 17:40:43	1.13
+++ loncom/homework/lonmaxima.pm	2007/08/13 10:21:46	1.20
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Interface routines to MAXIMA CAS
 #
-# $Id: lonmaxima.pm,v 1.13 2007/04/19 17:40:43 raeburn Exp $
+# $Id: lonmaxima.pm,v 1.20 2007/08/13 10:21:46 riegler Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -60,7 +60,10 @@ sub maximareply {
 
 sub blacklisted {
     my ($cmd)=@_;
-    foreach my $forbidden ('save','load','plot','lisp','includ','compil','file','batch','stringout','translat','stout','stin','block','system') {
+    foreach my $forbidden ('save','load','plot','lisp','includ','compil',
+			   'file','batch','stringout','translat','stout',
+			   'stin','block','system','concat','read','inchar',
+			   'outchar','ttyoff','with_stdout','writefile') {
 	if ($cmd=~/$forbidden/s) { return 1; }
     } 
     return 0;
@@ -75,7 +78,9 @@ sub runscript {
 	if ($line=~/\w/) { $reply=&maximareply($socket,$line.";\n"); }
 	if ($reply=~/^Error\:/) { return $reply; }
     }
-    $reply=~s/\W//gs;
+    $reply=~s/^\s*//gs;
+    $reply=~s/\s*$//gs;
+    &Apache::lonxml::debug("maxima $fullscript \n reply $reply");
     return $reply;
 }
 
@@ -117,7 +122,7 @@ sub maxima_eval {
 
 sub compareterms {
     my ($socket,$terma,$termb)=@_;
-    my $difference=$terma.'-'.$termb;
+    my $difference=$terma.'-('.$termb.')';
     if (&blacklisted($difference)) { return 'Error: blacklisted'; }
     my $reply=&maximareply($socket,'trigsimp(trigreduce('.$difference.'));');
     if ($reply=~/^\s*0\s*$/) { return 'true'; }
@@ -130,7 +135,10 @@ sub maxima_check {
     my $socket=&connect();
     my $reply=&compareterms($socket,$response,$answer);
     &disconnect($socket);
+    # integer to string mappings come from capaParser.h
+    # 1 maps to 'EXACT_ANS'
     if ($reply eq 'true') { return 1; }
+    # 7 maps to 'INCORRECT'
     return 7;
 }