diff --git a/src/test/java/PoliqarpPlusTreeTest.java b/src/test/java/PoliqarpPlusTreeTest.java
new file mode 100644
index 0000000..63437f2
--- /dev/null
+++ b/src/test/java/PoliqarpPlusTreeTest.java
@@ -0,0 +1,315 @@
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+import de.ids_mannheim.korap.query.serialize.PoliqarpPlusTree;
+
+public class PoliqarpPlusTreeTest {
+	
+	PoliqarpPlusTree ppt;
+	String map;
+
+	private boolean equalsContent(String str, Object map) {
+		str = str.replaceAll(" ", "");
+		String mapStr = map.toString().replaceAll(" ", "");
+		return str.equals(mapStr);
+	}
+	
+	private boolean equalsQueryContent(String res, String query) {
+		res = res.replaceAll(" ", "");
+		ppt = new PoliqarpPlusTree(query);
+		String queryMap = ppt.getRequestMap().get("query").toString().replaceAll(" ", "");
+		return res.equals(queryMap);
+	}
+	
+	@Test
+	public void testContext() {
+		String contextString = "{korap=http://korap.ids-mannheim.de/ns/query, @language=de, operands={@id=korap:operands, @container=@list}, relation={@id=korap:relation, @type=korap:relation#types}, class={@id=korap:class, @type=xsd:integer}, query=korap:query, filter=korap:filter, meta=korap:meta}";
+		ppt = new PoliqarpPlusTree("[base=test]");
+		assertTrue(equalsContent(contextString, ppt.getRequestMap().get("@context")));
+	}
+	
+	@Test
+	public void testSingleTokens() {
+		// [base=Mann]
+		String token1 = "{@type=korap:token, @value={@type=korap:term, @value=base:Mann, relation==}}";
+		assertTrue(equalsQueryContent(token1, "[base=Mann]"));
+		
+		// [orth!=Frau]
+		String token2 = "{@type=korap:token, @value={@type=korap:term, @value=orth:Frau, relation=!=}}";
+		assertTrue(equalsQueryContent(token2, "[orth!=Frau]"));
+		
+		// [!p=NN]
+		String token3 = "{@type=korap:token, @value={@type=korap:term, @value=p:NN, relation=!=}}";
+		assertTrue(equalsQueryContent(token3, "[!p=NN]"));
+		
+		// [!p!=NN]
+		String token4 = "{@type=korap:token, @value={@type=korap:term, @value=p:NN, relation==}}";
+		assertTrue(equalsQueryContent(token4, "[!p!=NN]"));
+	}
+	
+	@Test
+	public void testElements() {
+		// <s>
+		String elem1 = "{@type=korap:element, @value=s}";
+		assertTrue(equalsQueryContent(elem1, "<s>"));
+		
+		// <vp>
+		String elem2 = "{@type=korap:element, @value=vp}";
+		assertTrue(equalsQueryContent(elem2, "<vp>"));
+	}
+
+	@Test
+	public void testCoordinatedFields() {
+		// [base=Mann&(cas=N|cas=A)]
+		String cof1 = 
+			"{@type=korap:token, @value=" +
+				"{@type=korap:group, operands=[" +
+					"{@type=korap:term, @value=base:Mann, relation==}," +
+					"{@type=korap:group, operands=[" +
+						"{@type=korap:term, @value=cas:N, relation==}," +
+						"{@type=korap:term, @value=cas:A, relation==}" +
+					"], relation=or}" +
+				"], relation=and}" +
+			"}";
+		ppt = new PoliqarpPlusTree("[base=Mann&(cas=N|cas=A)]");
+		map = ppt.getRequestMap().get("query").toString();
+		assertEquals(cof1.replaceAll(" ", ""), map.replaceAll(" ", ""));
+	}
+	
+	@Test
+	public void testOccurrence() {
+	}
+	
+	@Test
+	public void testTokenSequence() {
+		// [base=Mann][orth=Frau]
+		String seq1 = "{@type=korap:sequence, operands=[" +
+				"{@type=korap:token, @value={@type=korap:term, @value=base:Mann, relation==}}, " +
+				"{@type=korap:token, @value={@type=korap:term, @value=orth:Frau, relation==}}" +
+				"]}";
+		assertTrue(equalsQueryContent(seq1, "[base=Mann][orth=Frau]"));
+		
+		// [base=Mann][orth=Frau][p=NN]
+		String seq2 = "{@type=korap:sequence, operands=[" +
+				"{@type=korap:token, @value={@type=korap:term, @value=base:Mann, relation==}}, " +
+				"{@type=korap:token, @value={@type=korap:term, @value=orth:Frau, relation==}}, " +
+				"{@type=korap:token, @value={@type=korap:term, @value=p:NN, relation==}}" +
+				"]}";
+		assertTrue(equalsQueryContent(seq2, "[base=Mann][orth=Frau][p=NN]"));
+	}
+	
+	@Test
+	public void testTokenElemSequence() {
+		// [base=Mann]<vp>
+		String seq1 = "{@type=korap:sequence, operands=[" +
+				"{@type=korap:token, @value={@type=korap:term, @value=base:Mann, relation==}}, " +
+				"{@type=korap:element, @value=vp}" +
+				"]}";
+		assertTrue(equalsQueryContent(seq1, "[base=Mann]<vp>"));
+		
+		// <vp>[base=Mann]
+		String seq2 = "{@type=korap:sequence, operands=[" +
+				"{@type=korap:element, @value=vp}, "+
+				"{@type=korap:token, @value={@type=korap:term, @value=base:Mann, relation==}} " +
+				"]}";
+		assertTrue(equalsQueryContent(seq2, "<vp>[base=Mann]"));
+		
+		// <vp>[base=Mann]<pp>
+		String seq3 = "{@type=korap:sequence, operands=[" +
+				"{@type=korap:element, @value=vp}, "+
+				"{@type=korap:token, @value={@type=korap:term, @value=base:Mann, relation==}}, " +
+				"{@type=korap:element, @value=pp} "+
+				"]}";
+		assertTrue(equalsQueryContent(seq3, "<vp>[base=Mann]<pp>"));
+	}
+	
+	@Test
+	public void testElemSequence() {
+		// <np><vp>
+		String seq1 = "{@type=korap:sequence, operands=[" +
+				"{@type=korap:element, @value=np}," +
+				"{@type=korap:element, @value=vp}" +
+				"]}";
+		assertTrue(equalsQueryContent(seq1, "<np><vp>"));
+		
+		// <np><vp><pp>
+		String seq2 = "{@type=korap:sequence, operands=[" +
+				"{@type=korap:element, @value=np}," +
+				"{@type=korap:element, @value=vp}," +
+				"{@type=korap:element, @value=pp}" +
+				"]}";
+		assertTrue(equalsQueryContent(seq2, "<np><vp><pp>"));
+	}
+	
+	@Test 
+	public void testClasses() {
+		// {[base=Mann]}
+		String cls1 = "{@type=korap:group, class=0, operands=[" +
+				"{@type=korap:token, @value={@type=korap:term, @value=base:Mann, relation==}}" +
+				"]}";
+		assertTrue(equalsQueryContent(cls1, "{[base=Mann]}"));
+		
+		// {[base=Mann][orth=Frau]}
+		String cls2 = "{@type=korap:group, class=0, operands=[" +
+				 "{@type=korap:sequence, operands=[" +
+				  "{@type=korap:token, @value={@type=korap:term, @value=base:Mann, relation==}}," +
+				  "{@type=korap:token, @value={@type=korap:term, @value=orth:Frau, relation==}}" +
+				 "]}" +
+				"]}";
+		assertTrue(equalsQueryContent(cls2, "{[base=Mann][orth=Frau]}"));
+		
+		// [p=NN]{[base=Mann][orth=Frau]}
+		String cls3 = "{@type=korap:sequence, operands=[" +
+						"{@type=korap:token, @value={@type=korap:term, @value=p:NN, relation==}}," +
+						"{@type=korap:group, class=0, operands=[" +
+							"{@type=korap:sequence, operands=[" +
+								"{@type=korap:token, @value={@type=korap:term, @value=base:Mann, relation==}}," +
+								"{@type=korap:token, @value={@type=korap:term, @value=orth:Frau, relation==}}" +
+							"]}" +
+						"]}" +
+					  "]}";
+		assertTrue(equalsQueryContent(cls3, "[p=NN]{[base=Mann][orth=Frau]}"));
+		
+		// {[base=Mann][orth=Frau]}[p=NN]
+		String cls4 = "{@type=korap:sequence, operands=[" +
+						"{@type=korap:group, class=0, operands=[" +
+						   "{@type=korap:sequence, operands=[" +
+						     "{@type=korap:token, @value={@type=korap:term, @value=base:Mann, relation==}}," +
+						     "{@type=korap:token, @value={@type=korap:term, @value=orth:Frau, relation==}}" +
+						   "]}" +
+						"]}," +
+						"{@type=korap:token, @value={@type=korap:term, @value=p:NN, relation==}}" +
+					  "]}";
+		assertTrue(equalsQueryContent(cls4, "{[base=Mann][orth=Frau]}[p=NN]"));
+	}
+	
+	@Test
+	public void testPositions() {
+		// contains(<s>,<np>)
+		String pos1 = "{@type=korap:group, relation=position, position=contains, operands=[" +
+				  "{@type=korap:element, @value=s}," +
+				  "{@type=korap:element, @value=np}" +
+				"]}";
+		assertTrue(equalsQueryContent(pos1, "contains(<s>,<np>)"));
+		
+		// contains(<s>,[base=Mann])
+		String pos2 = "{@type=korap:group, relation=position, position=contains, operands=[" +
+				  "{@type=korap:element, @value=s}," +
+				  "{@type=korap:token, @value= {@type=korap:term, @value=base:Mann, relation==}}" +
+				"]}";
+		assertTrue(equalsQueryContent(pos2, "contains(<s>,[base=Mann])"));
+		
+		// contains(<s>,[orth=der][orth=Mann])
+		String pos3 = "{@type=korap:group, relation=position, position=contains, operands=[" +
+				  	"{@type=korap:element, @value=s}," +
+				  	"{@type=korap:sequence, operands=[" +
+				  		"{@type=korap:token, @value={@type=korap:term, @value=orth:der, relation==}}," +
+				  		"{@type=korap:token, @value={@type=korap:term, @value=orth:Mann, relation==}}" +
+				  	"]}" +
+				  "]}";
+		ppt = new PoliqarpPlusTree("contains(<s>,[orth=der][orth=Mann])");
+		map = ppt.getRequestMap().get("query").toString();
+		assertEquals(pos3.replaceAll(" ", ""), map.replaceAll(" ", ""));
+		
+		// [base=Auto]contains(<s>,[base=Mann])
+		String pos4 = 
+				"{@type=korap:sequence, operands=[" +
+					"{@type=korap:token, @value={@type=korap:term, @value=base:Auto, relation==}}," +
+					"{@type=korap:group, relation=position, position=contains, operands=[" +
+				  		"{@type=korap:element, @value=s}," +
+				  		"{@type=korap:token, @value={@type=korap:term, @value=base:Mann, relation==}}" +
+				  	"]}" +
+				"]}";
+		ppt = new PoliqarpPlusTree("[base=Auto]contains(<s>,[base=Mann])");
+		map = ppt.getRequestMap().get("query").toString();
+		assertEquals(pos4.replaceAll(" ", ""), map.replaceAll(" ", ""));
+	}
+	
+	@Test
+	public void testNestedPositions() {
+		// contains(<s>,startswith(<np>,[orth=Der]))
+		String npos1 = 
+			"{@type=korap:group, relation=position, position=contains, operands=[" +
+				"{@type=korap:element, @value=s}," +
+				"{@type=korap:group, relation=position, position=startswith, operands=[" +
+					"{@type=korap:element, @value=np}," +
+					"{@type=korap:token, @value={@type=korap:term, @value=orth:Der, relation==}}" +
+				"]}" +
+			"]}";
+		ppt = new PoliqarpPlusTree("contains(<s>,startswith(<np>,[orth=Der]))");
+		map = ppt.getRequestMap().get("query").toString();
+		assertEquals(npos1.replaceAll(" ", ""), map.replaceAll(" ", ""));
+	}
+	
+	@Test
+	public void testShrinkSplit() {
+		// shrink([orth=Der]{[orth=Mann]})
+		String shr1 = 
+			"{@type=korap:group, relation=shrink, shrink=0, operands=[" +
+				"{@type=korap:sequence, operands=[" +
+					"{@type=korap:token, @value={@type=korap:term, @value=orth:Der, relation==}}," +
+					"{@type=korap:group, class=0, operands=[" +
+						"{@type=korap:token, @value={@type=korap:term, @value=orth:Mann, relation==}}" +
+					"]}" +
+				"]}" +
+			"]}";
+		ppt = new PoliqarpPlusTree("shrink([orth=Der]{[orth=Mann]})");
+		map = ppt.getRequestMap().get("query").toString();
+		assertEquals(shr1.replaceAll(" ", ""), map.replaceAll(" ", ""));
+		
+		// shrink([orth=Der]{[orth=Mann][orth=geht]})
+		String shr2 = 
+			"{@type=korap:group, relation=shrink, shrink=0, operands=[" +
+				"{@type=korap:sequence, operands=[" +
+					"{@type=korap:token, @value={@type=korap:term, @value=orth:Der, relation==}}," +
+					"{@type=korap:group, class=0, operands=[" +
+						"{@type=korap:sequence, operands=[" +
+							"{@type=korap:token, @value={@type=korap:term, @value=orth:Mann, relation==}}," +
+							"{@type=korap:token, @value={@type=korap:term, @value=orth:geht, relation==}}" +
+						"]}" +
+					"]}" +
+				"]}" +
+			"]}";
+		ppt = new PoliqarpPlusTree("shrink([orth=Der]{[orth=Mann][orth=geht]})");
+		map = ppt.getRequestMap().get("query").toString();
+		assertEquals(shr2.replaceAll(" ", ""), map.replaceAll(" ", ""));
+		
+		// shrink(1:[orth=Der]{1:[orth=Mann][orth=geht]})
+		String shr3 = 
+			"{@type=korap:group, relation=shrink, shrink=1, operands=[" +
+				"{@type=korap:sequence, operands=[" +
+					"{@type=korap:token, @value={@type=korap:term, @value=orth:Der, relation==}}," +
+					"{@type=korap:group, class=1, operands=[" +
+						"{@type=korap:sequence, operands=[" +
+							"{@type=korap:token, @value={@type=korap:term, @value=orth:Mann, relation==}}," +
+							"{@type=korap:token, @value={@type=korap:term, @value=orth:geht, relation==}}" +
+						"]}" +
+					"]}" +
+				"]}" +
+			"]}";
+		ppt = new PoliqarpPlusTree("shrink(1:[orth=Der]{1:[orth=Mann][orth=geht]})");
+		map = ppt.getRequestMap().get("query").toString();
+		assertEquals(shr3.replaceAll(" ", ""), map.replaceAll(" ", ""));
+		
+		// shrink(1:startswith(<s>,{1:<np>}))
+		String shr4 = 
+			"{@type=korap:group, relation=shrink, shrink=1, operands=[" +
+				"{@type=korap:group, relation=position, position=startswith, operands=[" +
+					"{@type=korap:element, @value=s}," +
+					"{@type=korap:group, class=1, operands=[" +
+						"{@type=korap:element, @value=np}" +
+					"]}" +
+				"]}" +
+			"]}";
+		ppt = new PoliqarpPlusTree("shrink(1:startswith(<s>,{1:<np>}))");
+		map = ppt.getRequestMap().get("query").toString();
+		assertEquals(shr4.replaceAll(" ", ""), map.replaceAll(" ", ""));
+	}
+	
+	@Test
+	public void testLayers() {
+		
+	}
+}
+