diff --git a/src/main/java/swiss/sib/rdf/sparql/examples/SparqlInRdfToMermaid.java b/src/main/java/swiss/sib/rdf/sparql/examples/SparqlInRdfToMermaid.java
index 89eecfd2d..168c919f1 100644
--- a/src/main/java/swiss/sib/rdf/sparql/examples/SparqlInRdfToMermaid.java
+++ b/src/main/java/swiss/sib/rdf/sparql/examples/SparqlInRdfToMermaid.java
@@ -13,225 +13,42 @@
 import java.util.Set;
 import java.util.TreeMap;
 import java.util.stream.Collectors;
-import java.util.stream.IntStream;
 import java.util.stream.Stream;
 
-import org.eclipse.rdf4j.model.IRI;
-import org.eclipse.rdf4j.model.Literal;
 import org.eclipse.rdf4j.model.Model;
 import org.eclipse.rdf4j.model.Resource;
 import org.eclipse.rdf4j.model.Statement;
 import org.eclipse.rdf4j.model.Value;
-import org.eclipse.rdf4j.model.base.CoreDatatype;
 import org.eclipse.rdf4j.model.vocabulary.RDF;
 import org.eclipse.rdf4j.model.vocabulary.SHACL;
 import org.eclipse.rdf4j.query.MalformedQueryException;
-import org.eclipse.rdf4j.query.algebra.LeftJoin;
-import org.eclipse.rdf4j.query.algebra.Service;
-import org.eclipse.rdf4j.query.algebra.StatementPattern;
 import org.eclipse.rdf4j.query.algebra.TupleExpr;
-import org.eclipse.rdf4j.query.algebra.Var;
-import org.eclipse.rdf4j.query.algebra.helpers.AbstractQueryModelVisitor;
 import org.eclipse.rdf4j.query.parser.ParsedQuery;
 import org.eclipse.rdf4j.query.parser.QueryParser;
 import org.eclipse.rdf4j.query.parser.sparql.SPARQLParserFactory;
 
-
-
+import swiss.sib.rdf.sparql.examples.mermaid.FindWhichConstantsAreNotOnlyUsedAsPredicates;
+import swiss.sib.rdf.sparql.examples.mermaid.NameVariablesAndConstants;
+import swiss.sib.rdf.sparql.examples.mermaid.Render;
 import swiss.sib.rdf.sparql.examples.vocabularies.SIB;
 import swiss.sib.rdf.sparql.examples.vocabularies.SchemaDotOrg;
 
 public class SparqlInRdfToMermaid {
-	private static final class Render extends AbstractQueryModelVisitor<RuntimeException> {
-		private final Map<String, String> variableKeys;
-		private final Map<String, String> iriPrefixes;
-		private final Map<Value, String> constantKeys;
-		private final Set<Value> usedAsNode;
-		private final Map<String, String> anonymousKeys;
-		private final List<String> rq;
-		private int indent = 2;
-		private boolean optional;
-		
-		private Render(Map<String, String> variableKeys, Map<String, String> iriPrefixes,
-				Map<Value, String> constantKeys, Set<Value> usedAsNode, Map<String, String> anonymousKeys,
-				List<String> rq) {
-			this.variableKeys = variableKeys;
-			this.iriPrefixes = iriPrefixes;
-			this.constantKeys = constantKeys;
-			this.usedAsNode = usedAsNode;
-			this.anonymousKeys = anonymousKeys;
-			this.rq = rq;
-		}
 
-		@Override
-		public void meet(StatementPattern node) throws RuntimeException {
-			String subj = asString(node.getSubjectVar());
-			String obj = asString(node.getObjectVar());
-			if (node.getPredicateVar().isConstant() && !usedAsNode.contains(node.getPredicateVar().getValue())) {
-				String pred = prefix(node.getPredicateVar().getValue(), iriPrefixes);
-				rq.add(print(subj, obj, pred));
-			} else {
-				String pred = asString(node.getPredicateVar());
-				rq.add(indent() + subj + " -->" + pred + "--> "
-						+ obj);
-			}
-			super.meet(node);
-		}
-
-		private String print(String subj, String obj, String pred) {
-			String arrB = "--";
-			String arrE = "-->";
-			if (optional) {
-				arrB = "-.";
-				arrE = ".->";
-				optional=false; // Afterwards they should be solid again
-			}
-			return indent() + subj + arrB + pred + arrE +" "
-					+ obj;
-		}
-		
-		@Override
-		public void meet(LeftJoin s) throws RuntimeException {
-			s.getLeftArg().visit(this);
-			optional=true;
-			rq.add(indent()+"%%optional");
-			indent+=2;
-			s.getRightArg().visit(this);
-			indent-=2;
-		}
-
-		@Override
-		public void meet(Service s) throws RuntimeException {
-			rq.add(indent()+"subgraph \"" + s.getServiceRef().getValue().stringValue()+'"');
-			indent+=2;
-			rq.add(indent()+"direction LR");
-			super.meet(s);
-			indent-=2;
-			rq.add(indent()+"end");
-		}
-
-		private String indent() {
-			return IntStream.range(0, indent).mapToObj(i -> " ").collect(Collectors.joining());
-		}
-
-		private String asString(Var v) {
-			if (v.isAnonymous() && !v.isConstant()) {
-				return anonymousKeys.get(v.getName());
-			} else if (v.isConstant()) {
-				return constantKeys.get(v.getValue());
-			} else {
-				return variableKeys.get(v.getName());
-			}
-		}
-	}
-
-	private static final class FindWhichConstantsAreNotOnlyUsedAsPredicates
-			extends AbstractQueryModelVisitor<RuntimeException> {
-		private final Set<Value> usedAsNode;
-
-		private FindWhichConstantsAreNotOnlyUsedAsPredicates(Set<Value> usedAsNode) {
-			this.usedAsNode = usedAsNode;
-		}
-
-		@Override
-		public void meet(StatementPattern node) throws RuntimeException {
-			if (node.getPredicateVar().isConstant()) {
-				markAsUsed(node.getSubjectVar(), node.getObjectVar());
-			} else {
-				markAsUsed(node.getSubjectVar(), node.getPredicateVar(), node.getObjectVar());
-			}
-			super.meet(node);
-		}
-
-		private void markAsUsed(Var... vars) {
-			for (Var v : vars) {
-				usedAsNode.add(v.getValue());
-			}
-		}
-	}
-
-	public static final class NameVariablesAndConstants extends AbstractQueryModelVisitor<RuntimeException> {
-		private final Map<Value, String> constantKeys;
-		private final Map<String, String> variableKeys;
-		private final Map<String, String> anonymousKeys;
-
-		public NameVariablesAndConstants(Map<Value, String> constantKeys, Map<String, String> variableKeys,
-				Map<String, String> anonymousKeys) {
-			this.constantKeys = constantKeys;
-			this.variableKeys = variableKeys;
-			this.anonymousKeys = anonymousKeys;
-		}
-
-		@Override
-		public void meet(Var node) throws RuntimeException {
-			super.meet(node);
-			if (node.isAnonymous() && !node.isConstant()) {
-				if (!anonymousKeys.containsKey(node.getName())) {
-					String nextId = "a" + (anonymousKeys.size() + 1);
-					anonymousKeys.put(node.getName(), nextId);
-				}
-			} else if (!node.isConstant() && !variableKeys.containsKey(node.getName())) {
-				String nextId = "v" + (variableKeys.size() + 1);
-				variableKeys.put(node.getName(), nextId);
-
-			} else if (node.isConstant() && !constantKeys.containsKey(node.getValue())) {
-				String nextId = "c" + (constantKeys.size() + 1);
-				constantKeys.put(node.getValue(), nextId);
-			}
-		}
-
-	}
-
-	private static String prefix(String stringValue, Map<String, String> iriPrefixes) {
-		for (Map.Entry<String, String> en : iriPrefixes.entrySet()) {
-			if (stringValue.startsWith(en.getKey())) {
-				return '"' + en.getValue() + stringValue.substring(en.getKey().length()) + '"';
-			}
-		}
-		return stringValue;
-	}
-
-	private static String prefix(Value v, Map<String, String> iriPrefixes) {
-		if (v instanceof IRI i)
-			return prefix(i, iriPrefixes);
-		else if (v instanceof Literal l)
-			return prefix(l, iriPrefixes);
-		else
-			return v.stringValue();
-	}
-
-	private static String prefix(IRI stringValue, Map<String, String> iriPrefixes) {
-		return prefix(stringValue.stringValue(), iriPrefixes);
-	}
-
-	private static String prefix(Literal l, Map<String, String> iriPrefixes) {
-		CoreDatatype cd = l.getCoreDatatype();
-		if (cd.isXSDDatatype()) {
-			if (CoreDatatype.XSD.STRING.equals(cd))
-				return '"' + l.stringValue() + '"';
-			else if (cd.isXSDDatatype())
-				return '"' + l.stringValue() + "\"^^xsd:" + cd.getIri().getLocalName();
-			else if (cd.isRDFDatatype())
-				return '"' + l.stringValue() + "\"^^rdf:" + cd.getIri().getLocalName();
-			else if (cd.isGEODatatype())
-				return '"' + l.stringValue() + "\"^^geo:" + cd.getIri().getLocalName();
-		}
-		return '"' + l.stringValue() + "\"^^<" + l.getDatatype() + ">";
-	}
 
 	/**
-	 * {@link https://grlc.io/}
+	 * {@link https://mermaid.js.org}
 	 * 
 	 * @param ex the model containing all prefixes and query
-	 * @return a rq formatted list of strings that should be concatenated later.
+	 * @return a a mermaid string
 	 */
 	public static String asMermaid(Model ex) {
 		List<String> rq = new ArrayList<>();
+		rq.add("graph TD");
 
 		streamOf(ex, null, RDF.TYPE, SHACL.SPARQL_EXECUTABLE).map(Statement::getSubject).distinct().forEach(s -> {
-			rq.add("graph TD");
 			Stream.of(SHACL.ASK, SHACL.SELECT, SHACL.CONSTRUCT, SIB.DESCRIBE).flatMap(qt -> streamOf(ex, s, qt, null))
-					.forEach(q -> addPrefixes(q, ex, rq));
+					.forEach(q -> draw(q, ex, rq));
 		});
 		return rq.stream().collect(Collectors.joining("\n"));
 	}
@@ -241,7 +58,7 @@ public static String asMermaid(Model ex) {
 	 * 
 	 * @param rq
 	 **/
-	public static void addPrefixes(Statement queryId, Model ex, List<String> rq) {
+	public static void draw(Statement queryId, Model ex, List<String> rq) {
 		String query = queryId.getObject().stringValue();
 
 		String base = streamOf(ex, queryId.getSubject(), SchemaDotOrg.TARGET, null).map(Statement::getObject)
@@ -266,12 +83,7 @@ public static void addPrefixes(Statement queryId, Model ex, List<String> rq) {
 			tq.visit(new NameVariablesAndConstants(constantKeys, variableKeys, anonymousKeys));
 			tq.visit(new FindWhichConstantsAreNotOnlyUsedAsPredicates(usedAsNode));
 
-			addWithLeadingWhiteSpace(variableKeys.entrySet().stream().sorted(Comparator.comparing(Map.Entry::getKey))
-					.map(en -> en.getValue() + "(\"?" + en.getKey() + "\")"), rq);
-			addWithLeadingWhiteSpace(anonymousKeys.entrySet().stream().sorted(Comparator.comparing(Map.Entry::getKey))
-					.map(en -> en.getValue() + "((\"_:" + en.getValue() + "\"))"), rq);
-			addWithLeadingWhiteSpace(constantKeys.entrySet().stream().filter(en -> usedAsNode.contains(en.getKey()))
-					.map(en -> en.getValue() + "([" + prefix(en.getKey(), iriPrefixes) + "])"), rq);
+			
 			tq.visit(
 					new Render(variableKeys, iriPrefixes, constantKeys, usedAsNode, anonymousKeys, rq));
 
@@ -281,9 +93,7 @@ public static void addPrefixes(Statement queryId, Model ex, List<String> rq) {
 		}
 	}
 
-	private static void addWithLeadingWhiteSpace(Stream<String> map, List<String> rq) {
-		map.map(s -> "  " + s).forEach(rq::add);
-	}
+
 
 	private static void gatherCompleteQuery(Model ex, String query, Iterator<Statement> iterator,
 			StringBuilder prefixes, Map<String, String> iriPrefixes) {
diff --git a/src/main/java/swiss/sib/rdf/sparql/examples/mermaid/FindWhichConstantsAreNotOnlyUsedAsPredicates.java b/src/main/java/swiss/sib/rdf/sparql/examples/mermaid/FindWhichConstantsAreNotOnlyUsedAsPredicates.java
new file mode 100644
index 000000000..cf8850819
--- /dev/null
+++ b/src/main/java/swiss/sib/rdf/sparql/examples/mermaid/FindWhichConstantsAreNotOnlyUsedAsPredicates.java
@@ -0,0 +1,33 @@
+package swiss.sib.rdf.sparql.examples.mermaid;
+
+import java.util.Set;
+
+import org.eclipse.rdf4j.model.Value;
+import org.eclipse.rdf4j.query.algebra.StatementPattern;
+import org.eclipse.rdf4j.query.algebra.Var;
+import org.eclipse.rdf4j.query.algebra.helpers.AbstractQueryModelVisitor;
+
+public final class FindWhichConstantsAreNotOnlyUsedAsPredicates
+		extends AbstractQueryModelVisitor<RuntimeException> {
+	private final Set<Value> usedAsNode;
+
+	public FindWhichConstantsAreNotOnlyUsedAsPredicates(Set<Value> usedAsNode) {
+		this.usedAsNode = usedAsNode;
+	}
+
+	@Override
+	public void meet(StatementPattern node) throws RuntimeException {
+		if (node.getPredicateVar().isConstant()) {
+			markAsUsed(node.getSubjectVar(), node.getObjectVar());
+		} else {
+			markAsUsed(node.getSubjectVar(), node.getPredicateVar(), node.getObjectVar());
+		}
+		super.meet(node);
+	}
+
+	private void markAsUsed(Var... vars) {
+		for (Var v : vars) {
+			usedAsNode.add(v.getValue());
+		}
+	}
+}
\ No newline at end of file
diff --git a/src/main/java/swiss/sib/rdf/sparql/examples/mermaid/NameVariablesAndConstants.java b/src/main/java/swiss/sib/rdf/sparql/examples/mermaid/NameVariablesAndConstants.java
new file mode 100644
index 000000000..9de59da49
--- /dev/null
+++ b/src/main/java/swiss/sib/rdf/sparql/examples/mermaid/NameVariablesAndConstants.java
@@ -0,0 +1,39 @@
+package swiss.sib.rdf.sparql.examples.mermaid;
+
+import java.util.Map;
+
+import org.eclipse.rdf4j.model.Value;
+import org.eclipse.rdf4j.query.algebra.Var;
+import org.eclipse.rdf4j.query.algebra.helpers.AbstractQueryModelVisitor;
+
+public final class NameVariablesAndConstants extends AbstractQueryModelVisitor<RuntimeException> {
+	private final Map<Value, String> constantKeys;
+	private final Map<String, String> variableKeys;
+	private final Map<String, String> anonymousKeys;
+
+	public NameVariablesAndConstants(Map<Value, String> constantKeys, Map<String, String> variableKeys,
+			Map<String, String> anonymousKeys) {
+		this.constantKeys = constantKeys;
+		this.variableKeys = variableKeys;
+		this.anonymousKeys = anonymousKeys;
+	}
+
+	@Override
+	public void meet(Var node) throws RuntimeException {
+		super.meet(node);
+		if (node.isAnonymous() && !node.isConstant()) {
+			if (!anonymousKeys.containsKey(node.getName())) {
+				String nextId = "a" + (anonymousKeys.size() + 1);
+				anonymousKeys.put(node.getName(), nextId);
+			}
+		} else if (!node.isConstant() && !variableKeys.containsKey(node.getName())) {
+			String nextId = "v" + (variableKeys.size() + 1);
+			variableKeys.put(node.getName(), nextId);
+
+		} else if (node.isConstant() && !constantKeys.containsKey(node.getValue())) {
+			String nextId = "c" + (constantKeys.size() + 1);
+			constantKeys.put(node.getValue(), nextId);
+		}
+	}
+
+}
\ No newline at end of file
diff --git a/src/main/java/swiss/sib/rdf/sparql/examples/mermaid/Render.java b/src/main/java/swiss/sib/rdf/sparql/examples/mermaid/Render.java
new file mode 100644
index 000000000..acc94ebd8
--- /dev/null
+++ b/src/main/java/swiss/sib/rdf/sparql/examples/mermaid/Render.java
@@ -0,0 +1,261 @@
+package swiss.sib.rdf.sparql.examples.mermaid;
+
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
+import org.eclipse.rdf4j.model.IRI;
+import org.eclipse.rdf4j.model.Literal;
+import org.eclipse.rdf4j.model.Value;
+import org.eclipse.rdf4j.model.base.CoreDatatype;
+import org.eclipse.rdf4j.model.vocabulary.RDF;
+import org.eclipse.rdf4j.query.algebra.Compare;
+import org.eclipse.rdf4j.query.algebra.Exists;
+import org.eclipse.rdf4j.query.algebra.Filter;
+import org.eclipse.rdf4j.query.algebra.LeftJoin;
+import org.eclipse.rdf4j.query.algebra.Not;
+import org.eclipse.rdf4j.query.algebra.SameTerm;
+import org.eclipse.rdf4j.query.algebra.Service;
+import org.eclipse.rdf4j.query.algebra.StatementPattern;
+import org.eclipse.rdf4j.query.algebra.Union;
+import org.eclipse.rdf4j.query.algebra.Var;
+import org.eclipse.rdf4j.query.algebra.helpers.AbstractQueryModelVisitor;
+
+public final class Render extends AbstractQueryModelVisitor<RuntimeException> {
+	private final class FindNodesUsedInFilter extends AbstractQueryModelVisitor<RuntimeException> {
+		private final String filterId;
+
+		private FindNodesUsedInFilter(String filterId) {
+			this.filterId = filterId;
+		}
+
+		@Override
+		public void meet(Var node) throws RuntimeException {
+			rq.add(indent() + filterId + " .-> " + asString(node));
+		}
+		
+		@Override
+		public void meet(SameTerm node) throws RuntimeException {
+			rq.add(indent() + filterId + "{{ sameTerm }}");
+			super.meet(node);
+		}
+
+		@Override
+		public void meet(Not node) throws RuntimeException {
+			rq.add(indent() + filterId + "{{ Not }}");
+			super.meet(node);
+		}
+		
+		@Override
+		public void meet(Exists node) throws RuntimeException {
+			rq.add(indent() + "subgraph " + filterId + "{{ Exists }}");
+			Map<Value, String> constantKeys = new HashMap<>();
+			Map<String, String> variableKeys = new HashMap<>();
+			Map<String, String> anonymousKeys = new HashMap<>();
+			Set<Value> usedAsNode = new HashSet<>();
+			
+			node.visit(new NameVariablesAndConstants(constantKeys, variableKeys, anonymousKeys));
+			node.visit(new FindWhichConstantsAreNotOnlyUsedAsPredicates(usedAsNode));
+			node.visit(new Render(variableKeys, iriPrefixes, constantKeys, usedAsNode, anonymousKeys, rq));
+			
+		}
+		
+		@Override
+		public void meet(Compare node) throws RuntimeException {
+			switch(node.getOperator()) {
+				case EQ ->
+					rq.add(indent() + filterId + "{{ = }}");
+				case NE ->
+					rq.add(indent() + filterId + "{{ != }}");
+				case LT ->
+					rq.add(indent() + filterId + "{{ < }}");
+				case GT ->
+					rq.add(indent() + filterId + "{{ > }}");
+				case LE ->
+					rq.add(indent() + filterId + "{{ <= }}");
+				case GE ->
+					rq.add(indent() + filterId + "{{ >= }}");
+			}
+			super.meet(node);
+		}
+	}
+
+	private final Map<String, String> variableKeys;
+	private final Map<String, String> iriPrefixes;
+	private final Map<Value, String> constantKeys;
+	private final Set<Value> usedAsNode;
+	private final Map<Value, String> serviceKeys = new HashMap<>();
+	private final Map<String, String> anonymousKeys;
+	private final List<String> rq;
+	private int indent = 2;
+	private int optionalCount = 0;
+	private int unionCount = 0;
+	private boolean optional;
+	private int filterCount;
+
+	public Render(Map<String, String> variableKeys, Map<String, String> iriPrefixes, Map<Value, String> constantKeys,
+			Set<Value> usedAsNode, Map<String, String> anonymousKeys, List<String> rq) {
+		this.variableKeys = variableKeys;
+		this.iriPrefixes = iriPrefixes;
+		this.constantKeys = constantKeys;
+		this.usedAsNode = usedAsNode;
+		this.anonymousKeys = anonymousKeys;
+		this.rq = rq;
+		addWithLeadingWhiteSpace(variableKeys.entrySet().stream().sorted(Comparator.comparing(Map.Entry::getKey))
+				.map(en -> en.getValue() + "(\"?" + en.getKey() + "\")"), rq);
+		addWithLeadingWhiteSpace(anonymousKeys.entrySet().stream().sorted(Comparator.comparing(Map.Entry::getKey))
+				.map(en -> en.getValue() + "((\"_:" + en.getValue() + "\"))"), rq);
+		addWithLeadingWhiteSpace(constantKeys.entrySet().stream().filter(en -> usedAsNode.contains(en.getKey()))
+				.map(en -> en.getValue() + "([" + prefix(en.getKey(), iriPrefixes) + "])"), rq);
+		addStyles(rq);
+	}
+
+	private void addStyles(List<String> rq2) {
+//		rq2.add("classdef service fill:#f96");
+	}
+
+	private static void addWithLeadingWhiteSpace(Stream<String> map, List<String> rq) {
+		map.map(s -> "  " + s).forEach(rq::add);
+	}
+
+	@Override
+	public void meet(StatementPattern node) throws RuntimeException {
+		String subj = asString(node.getSubjectVar());
+		String obj = asString(node.getObjectVar());
+		if (node.getPredicateVar().isConstant() && !usedAsNode.contains(node.getPredicateVar().getValue())) {
+			String pred = prefix(node.getPredicateVar().getValue(), iriPrefixes);
+			rq.add(print(subj, obj, pred));
+		} else {
+			String pred = asString(node.getPredicateVar());
+			rq.add(indent() + subj + " -->" + pred + "--> " + obj);
+		}
+		super.meet(node);
+	}
+
+	private String print(String subj, String obj, String pred) {
+		String arrB = "--";
+		String arrE = "-->";
+		if (optional) {
+			arrB = "-.";
+			arrE = ".->";
+			optional = false; // Afterwards they should be solid again
+		}
+		return indent() + subj + arrB + pred + arrE + " " + obj;
+	}
+
+	@Override
+	public void meet(Filter f) throws RuntimeException {
+		String filterId = "f"+filterCount++;
+		
+		FindNodesUsedInFilter visitor = new FindNodesUsedInFilter(filterId);
+		f.getCondition().visit(visitor);
+		super.meet(f);
+	}
+	
+	@Override
+	public void meet(Union u) throws RuntimeException {
+		rq.add(indent() + "%%or");
+		rq.add(indent() + "subgraph union" + unionCount+"l[\" \"]");
+		indent += 2;
+		rq.add(indent() + "style union" + unionCount + "l fill:#abf,stroke-dasharray: 3 3;");
+		u.getRightArg().visit(this);
+		indent -= 2;
+		rq.add(indent() + "end");
+
+		rq.add(indent() + "subgraph union" + unionCount+"r[\" \"]");
+		indent += 2;
+		rq.add(indent() + "style union" + unionCount + "r fill:#abf,stroke-dasharray: 3 3;");
+		u.getLeftArg().visit(this);
+		indent -= 2;
+		rq.add(indent() + "end");
+		rq.add(indent() + "union"+unionCount+"r <== or ==> union" + unionCount+"l");
+		unionCount++;
+	}
+	
+	@Override
+	public void meet(LeftJoin s) throws RuntimeException {
+		s.getLeftArg().visit(this);
+		optional = true;
+		rq.add(indent() + "%%optional");
+		rq.add(indent() + "subgraph optional" + optionalCount+"[\"(optional)\"]");
+		rq.add(indent() + "style optional" + optionalCount++ + " fill:#bbf,stroke-dasharray: 5 5;");
+		indent += 2;
+		s.getRightArg().visit(this);
+		indent -= 2;
+		rq.add(indent() + "end");
+	}
+
+	@Override
+	public void meet(Service s) throws RuntimeException {
+		Value sv = s.getServiceRef().getValue();
+		String serviceIri = sv.stringValue();
+		String key = serviceKeys.computeIfAbsent(sv, (t) -> "s" + (serviceKeys.size() + 1));
+		rq.add(indent() + "subgraph " + key + "[\"" + serviceIri + "\"]");
+		indent += 2;
+		rq.add(indent() + "style " + key + " stroke-width:4px;");
+		super.meet(s);
+		indent -= 2;
+		rq.add(indent() + "end");
+	}
+
+	private String indent() {
+		return IntStream.range(0, indent).mapToObj(i -> " ").collect(Collectors.joining());
+	}
+
+	private String asString(Var v) {
+		if (v.isAnonymous() && !v.isConstant()) {
+			return anonymousKeys.get(v.getName());
+		} else if (v.isConstant()) {
+			return constantKeys.get(v.getValue());
+		} else {
+			return variableKeys.get(v.getName());
+		}
+	}
+
+	private static String prefix(Value v, Map<String, String> iriPrefixes) {
+		if (v instanceof IRI i)
+			return prefix(i, iriPrefixes);
+		else if (v instanceof Literal l)
+			return prefix(l, iriPrefixes);
+		else
+			return v.stringValue();
+	}
+
+	private static String prefix(String stringValue, Map<String, String> iriPrefixes) {
+		for (Map.Entry<String, String> en : iriPrefixes.entrySet()) {
+			if (stringValue.startsWith(en.getKey())) {
+				return '"' + en.getValue() + stringValue.substring(en.getKey().length()) + '"';
+			}
+		}
+		return stringValue;
+	}
+
+	private static String prefix(IRI stringValue, Map<String, String> iriPrefixes) {
+		if (RDF.TYPE.equals(stringValue)) {
+			return "\"a\"";
+		} else {
+			return prefix(stringValue.stringValue(), iriPrefixes);
+		}
+	}
+
+	private static String prefix(Literal l, Map<String, String> iriPrefixes) {
+		CoreDatatype cd = l.getCoreDatatype();
+		if (cd.isXSDDatatype()) {
+			if (CoreDatatype.XSD.STRING.equals(cd))
+				return '"' + l.stringValue() + '"';
+			else if (cd.isXSDDatatype())
+				return '"' + l.stringValue() + "^^xsd:" + cd.getIri().getLocalName() + '"';
+			else if (cd.isRDFDatatype())
+				return '"' + l.stringValue() + "^^rdf:" + cd.getIri().getLocalName() + '"';
+			else if (cd.isGEODatatype())
+				return '"' + l.stringValue() + "^^geo:" + cd.getIri().getLocalName() + '"';
+		}
+		return '"' + l.stringValue() + "^^<" + l.getDatatype() + ">\"";
+	}
+}
\ No newline at end of file
diff --git a/src/test/java/swiss/sib/rdf/sparql/examples/SparqlInRdfToMermaidTest.java b/src/test/java/swiss/sib/rdf/sparql/examples/SparqlInRdfToMermaidTest.java
index feee8e44d..9ed80dcdd 100644
--- a/src/test/java/swiss/sib/rdf/sparql/examples/SparqlInRdfToMermaidTest.java
+++ b/src/test/java/swiss/sib/rdf/sparql/examples/SparqlInRdfToMermaidTest.java
@@ -95,6 +95,7 @@ public class SparqlInRdfToMermaidTest {
 			  BIND(strafter(str(?ec),str(ec:)) as ?ecNumber)
 			  ?rhea rh:isTransport ?isTransport .
 			  ?rhea rh:equation [] .
+			  FILTER(?isTransport = true)
 			}''' . """;
 	
 	String simple = """