diff --git a/examples/cosmas17.json b/examples/cosmas17.json
index 32e073b..61333fd 100644
--- a/examples/cosmas17.json
+++ b/examples/cosmas17.json
@@ -2,20 +2,30 @@
   "context" : "http://ids-mannheim.de/ns/KorAP/json-ld/v0.1/context.jsonld",
   "query" : {
     "@type" : "korap:group",
-    "operation" : "operation:position",
-    "frame" : "frame:startswith",
+    "operation" : "operation:submatch",
+    "classRef" : [ 1 ],
     "operands" : [ {
-      "@type" : "korap:span",
-      "key" : "s"
-    }, {
-      "@type" : "korap:token",
-      "wrap" : {
-        "@type" : "korap:term",
-        "caseInsensitive" : true,
-        "key" : "wegen",
-        "layer" : "orth",
-        "match" : "match:eq"
-      }
+      "@type" : "korap:group",
+      "operation" : "operation:position",
+      "frame" : "frame:startswith",
+      "operands" : [ {
+        "@type" : "korap:span",
+        "key" : "s"
+      }, {
+        "@type" : "korap:group",
+        "operation" : "operation:class",
+        "class" : 1,
+        "operands" : [ {
+          "@type" : "korap:token",
+          "wrap" : {
+            "@type" : "korap:term",
+            "caseInsensitive" : true,
+            "key" : "wegen",
+            "layer" : "orth",
+            "match" : "match:eq"
+          }
+        } ]
+      } ]
     } ]
   }
 }
\ No newline at end of file
diff --git a/examples/cosmas18.json b/examples/cosmas18.json
index 4a8aa85..c27404e 100644
--- a/examples/cosmas18.json
+++ b/examples/cosmas18.json
@@ -3,7 +3,7 @@
   "query" : {
     "@type" : "korap:group",
     "operation" : "operation:submatch",
-    "@spanRef" : [ 0, 1 ],
+    "spanRef" : [ 0, 1 ],
     "operands" : [ {
       "@type" : "korap:span",
       "key" : "s"
diff --git a/examples/cosmas4.json b/examples/cosmas4.json
index 2040995..f241ecd 100644
--- a/examples/cosmas4.json
+++ b/examples/cosmas4.json
@@ -5,19 +5,15 @@
     "operation" : "operation:sequence",
     "inOrder" : true,
     "distances" : [ {
-      "@type" : "korap:group",
-      "operation" : "operation:and",
-      "operands" : [ {
-        "@type" : "korap:distance",
-        "key" : "w",
-        "min" : 1,
-        "max" : 3
-      }, {
-        "@type" : "korap:distance",
-        "key" : "s",
-        "min" : 1,
-        "max" : 1
-      } ]
+      "@type" : "korap:distance",
+      "key" : "w",
+      "min" : 1,
+      "max" : 3
+    }, {
+      "@type" : "korap:distance",
+      "key" : "s",
+      "min" : 1,
+      "max" : 1
     } ],
     "operands" : [ {
       "@type" : "korap:token",
diff --git a/examples/cosmas5.json b/examples/cosmas5.json
index 9b9222d..bc9748c 100644
--- a/examples/cosmas5.json
+++ b/examples/cosmas5.json
@@ -15,19 +15,15 @@
       "operation" : "operation:sequence",
       "inOrder" : true,
       "distances" : [ {
-        "@type" : "korap:group",
-        "operation" : "operation:and",
-        "operands" : [ {
-          "@type" : "korap:distance",
-          "key" : "w",
-          "min" : 1,
-          "max" : 3
-        }, {
-          "@type" : "korap:distance",
-          "key" : "s",
-          "min" : 1,
-          "max" : 1
-        } ]
+        "@type" : "korap:distance",
+        "key" : "w",
+        "min" : 1,
+        "max" : 3
+      }, {
+        "@type" : "korap:distance",
+        "key" : "s",
+        "min" : 1,
+        "max" : 1
       } ],
       "operands" : [ {
         "@type" : "korap:token",
diff --git a/examples/cosmas6.json b/examples/cosmas6.json
index 488d3af..a17a2b3 100644
--- a/examples/cosmas6.json
+++ b/examples/cosmas6.json
@@ -23,19 +23,15 @@
       "operation" : "operation:sequence",
       "inOrder" : true,
       "distances" : [ {
-        "@type" : "korap:group",
-        "operation" : "operation:and",
-        "operands" : [ {
-          "@type" : "korap:distance",
-          "key" : "w",
-          "min" : 1,
-          "max" : 3
-        }, {
-          "@type" : "korap:distance",
-          "key" : "s",
-          "min" : 1,
-          "max" : 1
-        } ]
+        "@type" : "korap:distance",
+        "key" : "w",
+        "min" : 1,
+        "max" : 3
+      }, {
+        "@type" : "korap:distance",
+        "key" : "s",
+        "min" : 1,
+        "max" : 1
       } ],
       "operands" : [ {
         "@type" : "korap:token",
diff --git a/examples/cosmas7.json b/examples/cosmas7.json
index aa430e8..15fa3b6 100644
--- a/examples/cosmas7.json
+++ b/examples/cosmas7.json
@@ -15,19 +15,15 @@
       "operation" : "operation:sequence",
       "inOrder" : true,
       "distances" : [ {
-        "@type" : "korap:group",
-        "operation" : "operation:and",
-        "operands" : [ {
-          "@type" : "korap:distance",
-          "key" : "w",
-          "min" : 1,
-          "max" : 3
-        }, {
-          "@type" : "korap:distance",
-          "key" : "s",
-          "min" : 1,
-          "max" : 1
-        } ]
+        "@type" : "korap:distance",
+        "key" : "w",
+        "min" : 1,
+        "max" : 3
+      }, {
+        "@type" : "korap:distance",
+        "key" : "s",
+        "min" : 1,
+        "max" : 1
       } ],
       "operands" : [ {
         "@type" : "korap:token",