--- loncom/homework/default_homework.lcpm	2016/12/06 20:51:11	1.171
+++ loncom/homework/default_homework.lcpm	2019/04/03 22:46:30	1.172.2.1
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA 
 # used by lonxml::xmlparse() as input variable $safeinit to Apache::run::run()
 #
-# $Id: default_homework.lcpm,v 1.171 2016/12/06 20:51:11 damieng Exp $
+# $Id: default_homework.lcpm,v 1.172.2.1 2019/04/03 22:46:30 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -632,16 +632,29 @@ sub hinton {
 sub random {
     my ($start,$end,$step)=@_;
     if ( ! $hidden::RANDOMINIT ) {
-	if ($external::randomseed == 0) { $external::randomseed=1; }
-	if ($external::randomseed =~/,/) {
-	    my ($num1,$num2)=split(/,/,$external::randomseed);
-	    &random_set_seed(1,abs($num1));
-	} elsif ($external::randomseed =~/:/) {
-	    my ($num1,$num2)=split(/:/,$external::randomseed);
-	    &random_set_seed(abs($num1),abs($num2));
-	} else {
-	    &random_set_seed(1,int(abs($external::randomseed)));
-	}
+        if ($external::randomseed == 0) { $external::randomseed=1; }
+        if ($external::randomseed =~/,/) {
+            my ($num1,$num2) = map { abs($_); } split(/,/,$external::randomseed);
+            if ((!$num1) || ($num1 > 2147483398)) {
+                &random_set_seed_from_phrase($external::randomseed);
+            } else {
+                &random_set_seed(1,$num1);
+            }
+        } elsif ($external::randomseed =~/:/) {
+            my ($num1,$num2) = map { abs($_); } split(/:/,$external::randomseed);
+            if ((!$num1) || (!$num2) || ($num1 > 2147483562) || ($num2 > 2147483398)) {
+                &random_set_seed_from_phrase($external::randomseed);
+            } else {
+                &random_set_seed($num1,$num2);
+            }
+        } else {
+            my $num1 = int(abs($external::randomseed));
+            if ((!$num1) || ($num1 > 2147483398)) {
+                &random_set_seed_from_phrase($external::randomseed);
+            } else {
+                &random_set_seed(1,$num1);
+            }
+        }
 	&math_random_uniform();
 	$hidden::RANDOMINIT=1;
     }
@@ -902,11 +915,19 @@ sub chemparse {
     my $formula = '';
     foreach my $token (@tokens) {
 	if ($token eq '->' ) {
-	    $formula .= '<m>\ensuremath{\rightarrow}</m> ';
+            if ($external::target eq 'web') {
+                $formula .= '&rarr; ';
+            } else {
+                $formula .= '<m>\ensuremath{\rightarrow}</m> ';
+	    }
 	    next;
 	}
 	if ($token eq '<-' ) {
-	    $formula .= '<m>\ensuremath{\leftarrow}</m> ';
+            if ($external::target eq 'web') {
+                $formula .= '&larr; ';
+            } else {
+                $formula .= '<m>\ensuremath{\leftarrow}</m> ';
+	    }
 	    next;
 	}  
 	if ($token eq '<=>') {