diff --git a/src/main/java/de/ids_mannheim/korap/query/spans/ExpandedExclusionSpans.java b/src/main/java/de/ids_mannheim/korap/query/spans/ExpandedExclusionSpans.java
index fe1a416..f406ef2 100644
--- a/src/main/java/de/ids_mannheim/korap/query/spans/ExpandedExclusionSpans.java
+++ b/src/main/java/de/ids_mannheim/korap/query/spans/ExpandedExclusionSpans.java
@@ -28,6 +28,8 @@
 	private boolean hasMoreNotClause;
 	private Spans notClause;
 	
+	private long matchCost;
+	
 	public ExpandedExclusionSpans(SpanExpansionQuery spanExpansionQuery,
 			AtomicReaderContext context, Bits acceptDocs,
 			Map<Term, TermContext> termContexts) throws IOException {
@@ -72,6 +74,7 @@
 				matchStartPosition = cs.getStart();
 				matchEndPosition = cs.getEnd();
 				matchPayload = cs.getPayloads();
+				matchCost = cs.getCost() + notClause.cost();
 				candidateSpans.remove(0);
 				return true;
 			}
@@ -213,7 +216,7 @@
 			payload.addAll(firstSpans.getPayload());
 		}
 		if (classNumber > 0 ){	
-		    // System.out.println("Extension offsets "+start+","+end);
+			//System.out.println("Extension offsets "+start+","+end);
 			payload.add(calculateExtensionOffsets(start, end));
 		}
 		return payload;
@@ -241,7 +244,6 @@
 
 	@Override
 	public long cost() {
-		// TODO Auto-generated method stub
-		return 0;
+		return matchCost;
 	}
 }
diff --git a/src/main/java/de/ids_mannheim/korap/query/spans/ExpandedSpans.java b/src/main/java/de/ids_mannheim/korap/query/spans/ExpandedSpans.java
index 68ae7f2..9000d4e 100644
--- a/src/main/java/de/ids_mannheim/korap/query/spans/ExpandedSpans.java
+++ b/src/main/java/de/ids_mannheim/korap/query/spans/ExpandedSpans.java
@@ -13,7 +13,7 @@
 
 import de.ids_mannheim.korap.query.SpanExpansionQuery;
 
-/**
+/** Spans expanded with min m tokens and max n tokens.
  * @author margaretha
  * */
 public class ExpandedSpans extends SimpleSpans{
@@ -45,16 +45,13 @@
 	}
 
 	private boolean advance() throws IOException {		
-		while (hasMoreSpans || candidateSpans.size() > 0) {
+		while (candidateSpans.size() > 0 || (hasMoreSpans = firstSpans.next())) {
 			if (candidateSpans.size() > 0 ){
 				setMatch(candidateSpans.get(0));
 				candidateSpans.remove(0);								
 				return true;
 			}
-			else {
-				hasMoreSpans = firstSpans.next();
-				setCandidateList();
-			}
+			else { setCandidateList(); }
 		}		
 		return false;
 	}
@@ -101,12 +98,10 @@
 			throws IOException{
 		
 		ArrayList<byte[]> payload = new ArrayList<byte[]>();
-		
-		if (classNumber > 0 ){					
-			if (firstSpans.isPayloadAvailable()){				
-				payload.addAll(firstSpans.getPayload());
-			}
-			
+		if (firstSpans.isPayloadAvailable()){				
+			payload.addAll(firstSpans.getPayload());
+		}
+		if (classNumber > 0 ){	
 			//System.out.println("Extension offsets "+start+","+end);
 			payload.add(calculateExtensionOffsets(start, end));
 		}
diff --git a/src/test/java/de/ids_mannheim/korap/index/TestSpanExpansionIndex.java b/src/test/java/de/ids_mannheim/korap/index/TestSpanExpansionIndex.java
index 1e575ef..b5379dd 100644
--- a/src/test/java/de/ids_mannheim/korap/index/TestSpanExpansionIndex.java
+++ b/src/test/java/de/ids_mannheim/korap/index/TestSpanExpansionIndex.java
@@ -38,7 +38,7 @@
 		SpanExpansionQuery seq = new SpanExpansionQuery(stq, 0, 2, -1, true);		
 		kr = ki.search(seq, (short) 10);
 		
-		assertEquals(72,kr.getTotalResults());
+		assertEquals(69,kr.getTotalResults());
 		assertEquals(5, kr.getMatch(0).getStartPos());
         assertEquals(8, kr.getMatch(0).getEndPos());
         assertEquals(6, kr.getMatch(1).getStartPos());
@@ -136,6 +136,7 @@
 	}
 	
 	/** Left expansion with exclusion
+	 * 	No expansion
 	 * */
 	@Test
 	public void testCase4() throws IOException {
@@ -163,4 +164,115 @@
 		
 	}
 	
+	/** Expansion over start and end documents
+	 * 	start => cut to 0
+	 * 	TODO: end => to be handled in rendering process
+	 * @throws IOException 
+	 * */
+	@Test
+	public void testCase5() throws IOException{
+		KorapIndex ki = new KorapIndex();
+		ki.addDoc(createFieldDoc0());
+		ki.commit();
+		
+		SpanTermQuery stq = new SpanTermQuery(new Term("base","s:e")	);
+		// left expansion precedes 0
+		SpanExpansionQuery seq = new SpanExpansionQuery(stq,2,2, -1, true);		
+		kr = ki.search(seq, (short) 10);
+		
+		assertEquals(4,kr.getTotalResults());
+		assertEquals(0, kr.getMatch(0).getStartPos());
+        assertEquals(2, kr.getMatch(0).getEndPos());
+        
+        //right expansion exceeds end position
+        seq = new SpanExpansionQuery(stq,3,3,0, true);		
+		kr = ki.search(seq, (short) 10);
+        		
+		assertEquals(4,kr.getTotalResults());
+		assertEquals(7, kr.getMatch(2).getStartPos());
+        assertEquals(11, kr.getMatch(2).getEndPos());
+        assertEquals(8, kr.getMatch(3).getStartPos());
+        assertEquals(12, kr.getMatch(3).getEndPos());        
+        		
+		/*for (KorapMatch km : kr.getMatches()){
+			System.out.println(km.getStartPos() +","+km.getEndPos()+" "
+					//+km.getSnippetBrackets()
+					);
+		}*/
+	}	
+	
+	/** Expansion exclusion : multiple documents
+	 * @throws IOException 
+	 * */
+	@Test
+	public void testCase6() throws IOException{
+		KorapIndex ki = new KorapIndex();
+		ki.addDoc(createFieldDoc0()); // same doc
+		ki.addDoc(createFieldDoc1()); // only not clause
+		ki.addDoc(createFieldDoc2()); // only main clause
+		ki.commit();
+		
+		SpanTermQuery stq = new SpanTermQuery(new Term("base","s:e"));
+		SpanTermQuery notQuery = new SpanTermQuery(new Term("base","s:d"));
+		
+		SpanExpansionQuery seq = new SpanExpansionQuery(stq, notQuery, 
+				2, 3, 0, true);		
+		kr = ki.search(seq, (short) 20);
+		
+		// notClause.doc() > firstSpans.doc()
+		assertEquals(7, kr.getMatch(0).getStartPos());
+        assertEquals(10, kr.getMatch(0).getEndPos());	
+        assertEquals(7, kr.getMatch(1).getStartPos());
+        assertEquals(11, kr.getMatch(1).getEndPos());
+        // !hasMoreNotClause
+        assertEquals(2, kr.getMatch(4).getLocalDocID());
+        assertEquals(1, kr.getMatch(4).getStartPos());
+        assertEquals(4, kr.getMatch(4).getEndPos());		
+	}
+	
+	private FieldDocument createFieldDoc0(){
+    	FieldDocument fd = new FieldDocument();
+        fd.addString("ID", "doc-0");
+        fd.addTV("base",
+            "ceccecdeec",             
+            "[(0-1)s:c|_0#0-1]" +
+            "[(1-2)s:e|_1#1-2]" +             
+            "[(2-3)s:c|_2#2-3]" +
+            "[(3-4)s:c|s:d|_3#3-4]" + 
+            "[(4-5)s:e|_4#4-5]" +             
+            "[(5-6)s:c|_5#5-6]" +
+            "[(6-7)s:d|_6#6-7]" +
+            "[(7-8)s:e|_7#7-8]" + 
+            "[(8-9)s:e|_8#8-9]" + 
+            "[(9-10)s:c|_9#9-10]");
+        return fd;
+    }
+	
+	private FieldDocument createFieldDoc1() {
+    	FieldDocument fd = new FieldDocument();
+        fd.addString("ID", "doc-1");
+        fd.addTV("base",
+            "bbccdd",             
+            "[(0-1)s:b|s:c|_1#0-1]" +
+            "[(1-2)s:b|_2#1-2]" +             
+            "[(2-3)s:c|_3#2-3]" +
+            "[(3-4)s:c|_4#3-4]" + 
+            "[(4-5)s:d|_5#4-5]" +             
+            "[(5-6)s:d|_6#5-6]");
+        return fd;
+	}
+	
+	private FieldDocument createFieldDoc2() {
+    	FieldDocument fd = new FieldDocument();
+        fd.addString("ID", "doc-2");
+        fd.addTV("base",
+            "text",             
+            "[(0-1)s:b|s:c|_1#0-1]" +
+            "[(1-2)s:e|_2#1-2]" +             
+            "[(2-3)s:c|_3#2-3]" +
+            "[(3-4)s:c|_4#3-4]" + 
+            "[(4-5)s:e|_5#4-5]" +             
+            "[(5-6)s:a|_6#5-6]");
+        return fd;
+	}
 }