diff --git a/lib/KorAP/Index/XIP/Constituency.pm b/lib/KorAP/Index/XIP/Constituency.pm
index 341a9da..ce43a7a 100644
--- a/lib/KorAP/Index/XIP/Constituency.pm
+++ b/lib/KorAP/Index/XIP/Constituency.pm
@@ -1,14 +1,21 @@
 package KorAP::Index::XIP::Constituency;
 use KorAP::Index::Base;
 use Set::Scalar;
+use Scalar::Util qw/weaken/;
 use v5.16;
 
+our $URI_RE = qr/^[^\#]+\#(.+?)$/;
+
 sub parse {
   my $self = shift;
 
-  # Collect all spans and check for roots
+  # Collect all spans
   my %xip_const;
+
+  # Collect all roots
   my $xip_const_root = Set::Scalar->new;
+
+  # Collect all non-roots
   my $xip_const_noroot = Set::Scalar->new;
 
   # First run:
@@ -19,25 +26,44 @@
     cb => sub {
       my ($stream, $span) = @_;
 
+      # Collect the span
       $xip_const{$span->id} = $span;
+
+      # It's probably a root
       $xip_const_root->insert($span->id);
 
       my $rel = $span->hash->{rel} or return;
       $rel = [$rel] unless ref $rel eq 'ARRAY';
 
       foreach (@$rel) {
-	if ($_->{-label} eq 'dominates' && $_->{-target}) {
-	  $xip_const_noroot->insert($_->{-target});
+	if ($_->{-label} eq 'dominates') {
+
+	  my $target = $_->{-target};
+	  if (!$target && $_->{-uri} &&
+		$_->{-uri} =~ $URI_RE)  {
+	    $target = $1;
+	  };
+
+	  next unless $target;
+
+	  # It's definately not a root
+	  $xip_const_noroot->insert($target);
 	};
       };
     }
   ) or return;
 
+  # Get the stream
   my $stream = $$self->stream;
 
+  # Recursive tree traversal method
   my $add_const = sub {
-    my $span = shift;
-    my $level = shift;
+    my ($span, $level) = @_;
+
+    weaken $xip_const_root;
+    weaken $xip_const_noroot;
+
+    # Get the correct position for the span
     my $mtt = $stream->pos($span->p_start);
 
     my $content = $span->hash;
@@ -54,6 +80,7 @@
       p_end => $span->p_end
     );
 
+    # Only add level payload if node != root
     $term{payload} = '<b>' . $level if $level;
 
     $mtt->add(%term);
@@ -64,14 +91,30 @@
     $rel = [$rel] unless ref $rel eq 'ARRAY';
 
     foreach (@$rel) {
-      next if $_->{-label} ne 'dominates' || !$_->{-target};
-      my $subspan = delete $xip_const{$_->{-target}} or return;
+      next if $_->{-label} ne 'dominates';
+      my $target;
+
+      $target = $_->{-target};
+      if (!$target && $_->{-uri} && $_->{-uri} =~ $URI_RE)  {
+	$target = $1;
+      };
+
+      next unless $target;
+
+      my $subspan = delete $xip_const{$target};
+      unless ($subspan) {
+	warn "Span " . $target . " not found";
+	return;
+      };
       $this->($subspan, $level + 1);
     };
   };
 
-  my $diff = $xip_const_root->difference($xip_const_noroot);
-  foreach ($diff->members) {
+  # Calculate all roots
+  my $roots = $xip_const_root->difference($xip_const_noroot);
+
+  # Start tree traversal from the root
+  foreach ($roots->members) {
     my $obj = delete $xip_const{$_} or next;
     $add_const->($obj, 0);
   };
@@ -79,6 +122,8 @@
   return 1;
 };
 
+
+# Layer info
 sub layer_info {
     ['xip/c=const']
 }
diff --git a/lib/KorAP/Index/XIP/Morpho.pm b/lib/KorAP/Index/XIP/Morpho.pm
index a6d0323..1eae6c6 100644
--- a/lib/KorAP/Index/XIP/Morpho.pm
+++ b/lib/KorAP/Index/XIP/Morpho.pm
@@ -19,7 +19,8 @@
       my $capital = 0;
       foreach (@$content) {
 	# pos
-	if (($_->{-name} eq 'pos') && ($found = $_->{'#text'})) {
+	if (($_->{-name} eq 'pos') &&
+	      ($found = $_->{'#text'})) {
 	  $mtt->add(
 	    term => 'xip/p:' . $found
 	  );
@@ -30,7 +31,8 @@
 
       foreach (@$content) {
 	# lemma
-	if (($_->{-name} eq 'lemma') && ($found = $_->{'#text'})) {
+	if (($_->{-name} eq 'lemma') &&
+	      ($found = $_->{'#text'})) {
 
 	  # Verb delimiter (aus=druecken)
 	  $mtt->add(term => 'xip/l:' . $found);
@@ -42,9 +44,6 @@
 	  my (@token) = split('#', $found);
 
 	  if (@token == 1) {
-#	    my $x = $token[0];
-#	    $x =~ s{/\w+$}{};
-#	    $mtt->add(term => 'xip/l:' . $x);
 	    next;
 	  };
 	  my $full = '';
@@ -53,12 +52,6 @@
 	    $_ =~ s{/\w+$}{};
 	    $mtt->add(term => 'xip/l:#' . $_);
 	  };
-#	  if (@token > 1) {
-#	    $full =~ s{/}{}g;
-#	    $full = lc $full;
-#	    $full = $capital ? ucfirst($full) : $full;
-#	    $mtt->add(term => 'xip/l:' . $full);
-#	  };
 	};
       };
     }) or return;
diff --git a/lib/KorAP/Tokenizer.pm b/lib/KorAP/Tokenizer.pm
index 5ac0e64..343a85c 100644
--- a/lib/KorAP/Tokenizer.pm
+++ b/lib/KorAP/Tokenizer.pm
@@ -175,8 +175,6 @@
     %param
   );
 
-  use Data::Dumper;
-
   my $spanarray = $spans->parse or return;
 
   if ($spans->should == $spans->have) {
diff --git a/lib/KorAP/Tokenizer/Range.pm b/lib/KorAP/Tokenizer/Range.pm
index a477820..5fa2a38 100644
--- a/lib/KorAP/Tokenizer/Range.pm
+++ b/lib/KorAP/Tokenizer/Range.pm
@@ -49,9 +49,17 @@
     return;
   };
 
-  if ($found =~ /!(\d+):(\d+)$/) {
+  if ($found =~ /^!(\d+):(\d+)$/) {
     return $2;
   };
 };
 
+
+sub to_string {
+  my $self = shift;
+  return join('', map {'['.join(',',@$_).']'}
+		@{$$self->get_range(0,100,'...')})
+    . '...';
+};
+
 1;
diff --git a/lib/KorAP/Tokenizer/Units.pm b/lib/KorAP/Tokenizer/Units.pm
index 5deead0..a073fef 100644
--- a/lib/KorAP/Tokenizer/Units.pm
+++ b/lib/KorAP/Tokenizer/Units.pm
@@ -24,7 +24,6 @@
   $span->o_end($to);
 
   my $start = $self->match->startswith($span->o_start);
-
   unless (defined $start) {
     $start = $self->range->after($span->o_start) or return;
   };
@@ -32,9 +31,11 @@
   $span->p_start($start);
 
   my $end = $self->match->endswith($span->o_end);
-  unless ($end) {
+
+  unless (defined $end) {
     $end = $self->range->before($span->o_end) or return;
   };
+
   # $span->p_end($end);
   # return unless $span->p_end >= $span->p_start;
 
@@ -57,11 +58,6 @@
 
   return unless defined $pos;
 
-#      if ($from == $to) {
-#	print "Unable to find match for $from - $to (resp ".$s->{-from} . '-' . $s->{-to}.") " . $s->{-id};
-#	print "\n";
-#      };
-
   my $token = KorAP::Tokenizer::Token->new;
   $token->id($s->{-id}) if $s && $s->{-id};
   $token->pos($pos);
diff --git a/t/artificial.t b/t/artificial.t
index 2addd6b..e4e5282 100644
--- a/t/artificial.t
+++ b/t/artificial.t
@@ -277,7 +277,7 @@
 ok($tokens = new_tokenizer->parse, 'New Tokenizer');
 
 # Add XIP/Sentences
-ok($tokens->add('XIP', 'Dependency'), 'Add XIP/Sentences');
+ok($tokens->add('XIP', 'Dependency'), 'Add XIP/Dependency');
 
 $stream = $tokens->stream;
 like($stream->pos(1)->to_string, qr!\|>:xip/d:NMOD\$<i>3!, 'Dependency fine');
@@ -311,6 +311,72 @@
 like($stream->pos(16)->to_string, qr!\|<xip/d:VMAIN\$<i>16!, 'Dependency fine');
 like($stream->pos(17)->to_string, qr!\|<:xip/d:AUXIL\$<i>16!, 'Dependency fine');
 
+# New instantiation
+ok($tokens = new_tokenizer->parse, 'New Tokenizer');
+
+# Add XIP/Sentences
+ok($tokens->add('XIP', 'Constituency'), 'Add XIP/Constituency');
+
+$stream = $tokens->stream;
+like($stream->pos(0)->to_string, qr!\|<>:xip/c:TOP#0-129\$<i>17!, 'Constituency fine');
+like($stream->pos(0)->to_string, qr!\|<>:xip/c:MC#0-129\$<i>17<b>1!, 'Constituency fine');
+like($stream->pos(0)->to_string, qr!\|<>:xip/c:PP#0-30\$<i>4<b>2!, 'Constituency fine');
+like($stream->pos(0)->to_string, qr!\|<>:xip/c:PREP#0-3\$<i>1!, 'Constituency fine');
+
+like($stream->pos(1)->to_string, qr!\|<>:xip/c:NP#4-30\$<i>4<b>3!, 'Constituency fine');
+like($stream->pos(1)->to_string, qr!\|<>:xip/c:NPA#4-30\$<i>4<b>4!, 'Constituency fine');
+like($stream->pos(1)->to_string, qr!\|<>:xip/c:AP#4-11\$<i>2<b>5!, 'Constituency fine');
+like($stream->pos(1)->to_string, qr!\|<>:xip/c:ADJ#4-11\$<i>2<b>6!, 'Constituency fine');
+
+like($stream->pos(2)->to_string, qr!\|<>:xip/c:AP#12-23\$<i>3<b>5!, 'Constituency fine');
+like($stream->pos(2)->to_string, qr!\|<>:xip/c:ADJ#12-23\$<i>3<b>6!, 'Constituency fine');
+
+like($stream->pos(3)->to_string, qr!\|<>:xip/c:NOUN#24-30\$<i>4<b>5!, 'Constituency fine');
+
+like($stream->pos(4)->to_string, qr!\|<>:xip/c:VERB#31-35\$<i>5<b>2!, 'Constituency fine');
+
+like($stream->pos(5)->to_string, qr!\|<>:xip/c:NP#36-47\$<i>7<b>2!, 'Constituency fine');
+like($stream->pos(5)->to_string, qr!\|<>:xip/c:DET#36-39\$<i>6<b>3!, 'Constituency fine');
+
+like($stream->pos(6)->to_string, qr!\|<>:xip/c:NPA#40-47\$<i>7<b>3!, 'Constituency fine');
+like($stream->pos(6)->to_string, qr!\|<>:xip/c:NOUN#40-47\$<i>7<b>4!, 'Constituency fine');
+
+like($stream->pos(7)->to_string, qr!\|<>:xip/c:NP#48-63\$<i>9<b>2!, 'Constituency fine');
+like($stream->pos(7)->to_string, qr!\|<>:xip/c:DET#48-51\$<i>8<b>3!, 'Constituency fine');
+
+like($stream->pos(8)->to_string, qr!\|<>:xip/c:NPA#52-63\$<i>9<b>3!, 'Constituency fine');
+like($stream->pos(8)->to_string, qr!\|<>:xip/c:NOUN#52-63\$<i>9<b>4!, 'Constituency fine');
+
+like($stream->pos(9)->to_string, qr!\|<>:xip/c:NP#64-73\$<i>10<b>2!, 'Constituency fine');
+like($stream->pos(9)->to_string, qr!\|<>:xip/c:NPA#64-73\$<i>10<b>3!, 'Constituency fine');
+like($stream->pos(9)->to_string, qr!\|<>:xip/c:NOUN#64-73\$<i>10<b>4!, 'Constituency fine');
+
+like($stream->pos(10)->to_string, qr!\|<>:xip/c:PTCL#74-77\$<i>11<b>2!, 'Constituency fine');
+
+like($stream->pos(11)->to_string, qr!\|<>:xip/c:SC#79-128\$<i>18!, 'Constituency fine');
+like($stream->pos(11)->to_string, qr!\|<>:xip/c:CONJ#79-84\$<i>12<b>1!, 'Constituency fine');
+
+like($stream->pos(12)->to_string, qr!\|<>:xip/c:NP#85-96\$<i>14<b>1!, 'Constituency fine');
+like($stream->pos(12)->to_string, qr!\|<>:xip/c:DET#85-88\$<i>13<b>2!, 'Constituency fine');
+
+
+like($stream->pos(13)->to_string, qr!\|<>:xip/c:NPA#89-96\$<i>14<b>2!, 'Constituency fine');
+like($stream->pos(13)->to_string, qr!\|<>:xip/c:NOUN#89-96\$<i>14<b>3!, 'Constituency fine');
+
+like($stream->pos(14)->to_string, qr!\|<>:xip/c:NP#97-101\$<i>15<b>1!, 'Constituency fine');
+like($stream->pos(14)->to_string, qr!\|<>:xip/c:NPA#97-101\$<i>15<b>2!, 'Constituency fine');
+like($stream->pos(14)->to_string, qr!\|<>:xip/c:NOUN#97-101\$<i>15<b>3!, 'Constituency fine');
+
+like($stream->pos(15)->to_string, qr!\|<>:xip/c:NP#102-111\$<i>16<b>1!, 'Constituency fine');
+like($stream->pos(15)->to_string, qr!\|<>:xip/c:NPA#102-111\$<i>16<b>2!, 'Constituency fine');
+like($stream->pos(15)->to_string, qr!\|<>:xip/c:NOUN#102-111\$<i>16<b>3!, 'Constituency fine');
+
+like($stream->pos(16)->to_string, qr!\|<>:xip/c:VERB#112-123\$<i>17<b>1!, 'Constituency fine');
+
+like($stream->pos(17)->to_string, qr!\|<>:xip/c:VERB#124-128\$<i>18<b>1!, 'Constituency fine');
+
+# diag $stream->to_string;
+
 
 # ADJA ADJA NN VVFIN ART NN ART NN NE PTKVZ KOUS ART NN NN NN VVPP VAFIN
 done_testing;
diff --git a/t/transform.t b/t/transform.t
index 63bc5a3..7387fe3 100644
--- a/t/transform.t
+++ b/t/transform.t
@@ -110,7 +110,7 @@
   ok($tokens->add(@$_), 'Add '. join(', ', @$_));
 };
 
-is($tokens->stream->pos(0)->to_string, '[(0-1)s:A|i:a|_0#0-1|-:tokens$<i>923|mate/p:XY|<>:base/s#0-74$<i>13|<>:base/text#0-6083$<i>923|-:base/sentences$<i>96|<>:base/para#0-224$<i>34|-:base/paragraphs$<i>76|opennlp/p:NE|<>:opennlp/s#0-74$<i>13|-:opennlp/sentences$<i>50|<>:corenlp/s#0-6$<i>2|-:corenlp/sentences$<i>65|cnx/l:A|cnx/p:N|cnx/syn:@NH|<>:cnx/s#0-74$<i>13|-:cnx/sentences$<i>62|tt/l:A|tt/p:NN|tt/l:A|tt/p:FM|<>:tt/s#0-6083$<i>923|-:tt/sentences$<i>1|>:mate/d:PNC$<i>2|xip/p:SYMBOL|xip/l:A|<>:xip/c:TOP#0-74$<i>13|<>:xip/c:MC#0-73$<i>13<b>1|>:xip/d:SUBJ$<i>3|<:xip/d:COORD$<i>1|<>:xip/s#0-74$<i>13|-:xip/sentences$<i>64]', 'Startinfo');
+is($tokens->stream->pos(0)->to_string, '[(0-1)s:A|i:a|_0#0-1|-:tokens$<i>923|mate/p:XY|<>:base/s#0-74$<i>13|<>:base/text#0-6083$<i>923|-:base/sentences$<i>96|<>:base/para#0-224$<i>34|-:base/paragraphs$<i>76|opennlp/p:NE|<>:opennlp/s#0-74$<i>13|-:opennlp/sentences$<i>50|<>:corenlp/s#0-6$<i>2|-:corenlp/sentences$<i>65|cnx/l:A|cnx/p:N|cnx/syn:@NH|<>:cnx/c:np#0-1$<i>1|<>:cnx/s#0-74$<i>13|-:cnx/sentences$<i>62|tt/l:A|tt/p:NN|tt/l:A|tt/p:FM|<>:tt/s#0-6083$<i>923|-:tt/sentences$<i>1|>:mate/d:PNC$<i>2|xip/p:SYMBOL|xip/l:A|<>:xip/c:TOP#0-74$<i>13|<>:xip/c:MC#0-73$<i>13<b>1|<>:xip/c:NP#0-1$<i>1<b>2|<>:xip/c:NPA#0-1$<i>1<b>3|<>:xip/c:NOUN#0-1$<i>1<b>4|<>:xip/c:SYMBOL#0-1$<i>1<b>5|>:xip/d:SUBJ$<i>3|<:xip/d:COORD$<i>1|<>:xip/s#0-74$<i>13|-:xip/sentences$<i>64]', 'Startinfo');
 
 
 is($tokens->stream->pos(118)->to_string,