diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 000000000..68cc094d8
Binary files /dev/null and b/.DS_Store differ
diff --git a/src/main/java/li/strolch/model/timedstate/ITimedState.java b/src/main/java/li/strolch/model/timedstate/ITimedState.java
new file mode 100644
index 000000000..a5d0a2744
--- /dev/null
+++ b/src/main/java/li/strolch/model/timedstate/ITimedState.java
@@ -0,0 +1,45 @@
+package li.strolch.model.timedstate;
+
+import li.strolch.model.timevalue.ITimeValue;
+import li.strolch.model.timevalue.ITimeVariable;
+import li.strolch.model.timevalue.IValue;
+import li.strolch.model.timevalue.IValueChange;
+
+/**
+ * A time based state characterized by a {@link IValue} object implementation.
+ * 
+ * @author martin_smock
+ * 
+ * @param <T>
+ *            IValue implementation representing the state at a given time
+ */
+@SuppressWarnings("rawtypes")
+public interface ITimedState<T extends IValue> {
+
+	/**
+	 * @return the new {@link ITimeValue} matching the value in the future
+	 */
+	ITimeValue<T> getNextMatch(final Long time, T value);
+
+	/**
+	 * @return the new {@link ITimeValue} matching the value in the future
+	 */
+	ITimeValue<T> getPreviousMatch(final Long time, T value);
+
+	/**
+	 * @param change
+	 *            the state change to be applied
+	 */
+	void applyChange(final IValueChange<T> change);
+
+	/**
+	 * @return the state at the given time
+	 */
+	ITimeValue<T> getStateAt(final Long time);
+
+	/**
+	 * @return get the states evolution in time
+	 */
+	ITimeVariable<T> getTimeEvolution();
+
+}
\ No newline at end of file
diff --git a/src/main/java/li/strolch/model/timedstate/TimedState.java b/src/main/java/li/strolch/model/timedstate/TimedState.java
new file mode 100644
index 000000000..f5dcfd089
--- /dev/null
+++ b/src/main/java/li/strolch/model/timedstate/TimedState.java
@@ -0,0 +1,64 @@
+package li.strolch.model.timedstate;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+import li.strolch.model.timevalue.ITimeValue;
+import li.strolch.model.timevalue.ITimeVariable;
+import li.strolch.model.timevalue.IValue;
+import li.strolch.model.timevalue.IValueChange;
+import li.strolch.model.timevalue.impl.TimeVariable;
+
+
+/**
+ * @author martin_smock
+ */
+@SuppressWarnings("rawtypes")
+public class TimedState<T extends IValue> implements ITimedState<T> {
+
+	private ITimeVariable<T> timeVariable = new TimeVariable<T>();
+
+	@Override
+	@SuppressWarnings("unchecked")
+	public ITimeValue<T> getNextMatch(final Long time, final T value) {
+		Collection<ITimeValue<T>> futureValues = timeVariable.getFutureValues(time);
+		for (ITimeValue<T> iTimeValue : futureValues) {
+			if (iTimeValue.getValue().matches(value)) {
+				return iTimeValue;
+			}
+		}
+		return null;
+	}
+
+	@Override
+	@SuppressWarnings("unchecked")
+	public ITimeValue<T> getPreviousMatch(final Long time, final T value) {
+		Collection<ITimeValue<T>> pastValues = timeVariable.getPastValues(time);
+		List<ITimeValue<T>> asList = new ArrayList<ITimeValue<T>>(pastValues);
+		Collections.reverse(asList);
+		for (ITimeValue<T> iTimeValue : asList) {
+			if (iTimeValue.getValue().matches(value)) {
+				return iTimeValue;
+			}
+		}
+		return null;
+	}
+
+	@Override
+	public void applyChange(final IValueChange<T> change) {
+		timeVariable.applyChange(change);
+	}
+
+	@Override
+	public ITimeValue<T> getStateAt(final Long time) {
+		return timeVariable.getValueAt(time);
+	}
+
+	@Override
+	public ITimeVariable<T> getTimeEvolution() {
+		return timeVariable;
+	}
+
+}
diff --git a/src/main/java/li/strolch/model/timevalue/ITimeValue.java b/src/main/java/li/strolch/model/timevalue/ITimeValue.java
new file mode 100644
index 000000000..1df712d26
--- /dev/null
+++ b/src/main/java/li/strolch/model/timevalue/ITimeValue.java
@@ -0,0 +1,24 @@
+package li.strolch.model.timevalue;
+
+import li.strolch.model.timevalue.impl.TimeVariable;
+
+/**
+ * Interface for timed value objects to be used with the {@link TimeVariable}
+ * 
+ * @author martin_smock
+ * 
+ * @param <T>
+ *            the backing value of the timed value object
+ */
+@SuppressWarnings("rawtypes")
+public interface ITimeValue<T extends IValue> extends Comparable<ITimeValue<T>> {
+
+	ITimeValue<T> setValue(final T value);
+
+	T getValue();
+
+	Long getTime();
+
+	ITimeValue<T> add(final T change);
+
+}
diff --git a/src/main/java/li/strolch/model/timevalue/ITimeVariable.java b/src/main/java/li/strolch/model/timevalue/ITimeVariable.java
new file mode 100644
index 000000000..4df20ff26
--- /dev/null
+++ b/src/main/java/li/strolch/model/timevalue/ITimeVariable.java
@@ -0,0 +1,70 @@
+package li.strolch.model.timevalue;
+
+import java.util.Collection;
+
+/**
+ * A timed variable storing a ordered sequence of {@link ITimeValue} objects
+ * modeling a time evolution of a quantity.
+ * 
+ * @author martin_smock
+ * 
+ * @param <T>
+ *            the backing value of the timed value object
+ */
+@SuppressWarnings("rawtypes")
+public interface ITimeVariable<T extends IValue> {
+
+	/**
+	 * set the value at a point in time to a given time value object
+	 * 
+	 * @param time
+	 *            the time to set the {@link IValue}
+	 * @param value
+	 *            the {@link IValue} to set
+	 */
+	void setValueAt(final Long time, final T value);
+
+	/**
+	 * get the latest {@link ITimeValue} whose time field is less or equal to
+	 * the time given
+	 */
+	ITimeValue<T> getValueAt(final Long time);
+
+	/**
+	 * Applies a {@link IValueChange} propagating the change to all future
+	 * values starting from the time of the change.
+	 * 
+	 * @param change
+	 *            the {@link IValueChange} to be applied
+	 */
+	void applyChange(final IValueChange<T> change);
+
+	/**
+	 * Get all {@link ITimeValue} objects whose time field is greater or equal
+	 * to the given time
+	 * 
+	 * @param time
+	 *            the time the sequence starts with
+	 * @return the sequence of {@link ITimeValue} objects in the future
+	 */
+	Collection<ITimeValue<T>> getFutureValues(final Long time);
+
+	/**
+	 * Get all {@link ITimeValue} objects whose time field is strictly smaller
+	 * than the given time
+	 * 
+	 * @param time
+	 *            the time the sequence starts with
+	 * @return the sequence of {@link ITimeValue} objects in the future
+	 */
+	Collection<ITimeValue<T>> getPastValues(final Long time);
+
+	/**
+	 * removes {@link ITimeValue} objects from the sequence, where the successor
+	 * matches value. I.e considering a pair of adjacent {@link ITimeValue}
+	 * objects in the sequence which have the same {@link IValue}, the later one
+	 * is removed, since it contains no additional information.
+	 */
+	void compact();
+
+}
diff --git a/src/main/java/li/strolch/model/timevalue/IValue.java b/src/main/java/li/strolch/model/timevalue/IValue.java
new file mode 100644
index 000000000..e3e4444ab
--- /dev/null
+++ b/src/main/java/li/strolch/model/timevalue/IValue.java
@@ -0,0 +1,41 @@
+package li.strolch.model.timevalue;
+
+/**
+ * A value object defining some basic algebraic operations. Mathematically
+ * speaking {@link IValue} objects define a group with a addition operation.
+ * 
+ * @author martin_smock
+ * 
+ * @param <T>
+ *            any object for which a (generalized) add operation can be defined.
+ * 
+ */
+public interface IValue<T> {
+
+	/**
+	 * @return the backing value
+	 */
+	T getValue();
+
+	/**
+	 * @return a value with the backing value added to the argument value
+	 */
+	IValue<T> add(T o);
+
+	/**
+	 * @return true, if the backing values match.
+	 */
+	boolean matches(IValue<T> other);
+
+	/**
+	 * @return the inverse value, such that add(value.getInverse()) returns the
+	 *         neutral element of the group
+	 */
+	IValue<T> getInverse();
+
+	/**
+	 * @return a copy of this
+	 */
+	IValue<T> getCopy();
+
+}
diff --git a/src/main/java/li/strolch/model/timevalue/IValueChange.java b/src/main/java/li/strolch/model/timevalue/IValueChange.java
new file mode 100644
index 000000000..ec25d5b18
--- /dev/null
+++ b/src/main/java/li/strolch/model/timevalue/IValueChange.java
@@ -0,0 +1,28 @@
+package li.strolch.model.timevalue;
+
+/**
+ * Interface for operators to be used to change the values of {@link ITimeValue}
+ * in a {@link ITimeVariable}.
+ * 
+ * @author martin_smock
+ */
+@SuppressWarnings("rawtypes")
+public interface IValueChange<T extends IValue> {
+
+	/**
+	 * @return the time this change has to be applied
+	 */
+	Long getTime();
+
+	/**
+	 * @return the value of the change
+	 */
+	T getValue();
+
+	/**
+	 * @return the inverse neutralizing a change. Very useful to undo changes
+	 *         applied.
+	 */
+	IValueChange<T> getInverse();
+
+}
diff --git a/src/main/java/li/strolch/model/timevalue/impl/AString.java b/src/main/java/li/strolch/model/timevalue/impl/AString.java
new file mode 100644
index 000000000..cd952facc
--- /dev/null
+++ b/src/main/java/li/strolch/model/timevalue/impl/AString.java
@@ -0,0 +1,69 @@
+package li.strolch.model.timevalue.impl;
+
+/**
+ * Wrapper for java.util.String object defining a inverse to support algebraic
+ * operations.
+ * 
+ * @author martin_smock
+ */
+public class AString {
+
+	private final String string;
+	private final boolean inverse;
+
+	public AString(final String string) {
+		this.string = string;
+		this.inverse = false;
+	}
+
+	public AString(final String string, final boolean inverse) {
+		this.string = string;
+		this.inverse = inverse;
+	}
+
+	public String getString() {
+		return string;
+	}
+
+	public boolean isInverse() {
+		return inverse;
+	}
+
+	public AString getInverse() {
+		return new AString(string, !inverse);
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + (inverse ? 1231 : 1237);
+		result = prime * result + ((string == null) ? 0 : string.hashCode());
+		return result;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		AString other = (AString) obj;
+		if (inverse != other.inverse)
+			return false;
+		if (string == null) {
+			if (other.string != null)
+				return false;
+		} else if (!string.equals(other.string))
+			return false;
+		return true;
+	}
+
+	@Override
+	public String toString() {
+		return "AString [string=" + string + ", inverse=" + inverse + "]";
+	}
+
+}
diff --git a/src/main/java/li/strolch/model/timevalue/impl/DoubleValue.java b/src/main/java/li/strolch/model/timevalue/impl/DoubleValue.java
new file mode 100644
index 000000000..f4a73fdff
--- /dev/null
+++ b/src/main/java/li/strolch/model/timevalue/impl/DoubleValue.java
@@ -0,0 +1,94 @@
+package li.strolch.model.timevalue.impl;
+
+import li.strolch.model.timevalue.ITimeValue;
+import li.strolch.model.timevalue.IValue;
+
+/**
+ * {@link IValue} implementation to work with Double valued {@link ITimeValue} objects
+ * 
+ * @author martin_smock
+ */
+public class DoubleValue implements IValue<Double> {
+
+	public static final DoubleValue NEUTRAL = new DoubleValue(0.0d);
+
+	private Double value;
+
+	public DoubleValue(Double value) {
+		this.value = value;
+	}
+
+	public DoubleValue(double value) {
+		this.value = Double.valueOf(value);
+	}
+
+	public DoubleValue(Integer value) {
+		this.value = this.value.doubleValue();
+	}
+
+	public DoubleValue(int value) {
+		this.value = Integer.valueOf(value).doubleValue();
+	}
+
+	public DoubleValue(String valueAsString) throws NumberFormatException {
+		this.value = Double.parseDouble(valueAsString);
+	}
+
+	@Override
+	public DoubleValue add(Double o) {
+		value += o;
+		return this;
+	}
+
+	@Override
+	public Double getValue() {
+		return value;
+	}
+
+	@Override
+	public String toString() {
+		return "DoubleValue [value=" + value + "]";
+	}
+
+	@Override
+	public boolean matches(IValue<Double> other) {
+		return this.value.equals(other.getValue());
+	}
+
+	@Override
+	public DoubleValue getInverse() {
+		return new DoubleValue(-getValue());
+	}
+
+	@Override
+	public DoubleValue getCopy(){
+		return new DoubleValue(value); 
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + ((value == null) ? 0 : value.hashCode());
+		return result;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		DoubleValue other = (DoubleValue) obj;
+		if (value == null) {
+			if (other.value != null)
+				return false;
+		} else if (!value.equals(other.value))
+			return false;
+		return true;
+	}
+	
+
+}
diff --git a/src/main/java/li/strolch/model/timevalue/impl/IntegerValue.java b/src/main/java/li/strolch/model/timevalue/impl/IntegerValue.java
new file mode 100644
index 000000000..6b1964318
--- /dev/null
+++ b/src/main/java/li/strolch/model/timevalue/impl/IntegerValue.java
@@ -0,0 +1,86 @@
+package li.strolch.model.timevalue.impl;
+
+import li.strolch.model.timevalue.ITimeValue;
+import li.strolch.model.timevalue.IValue;
+
+/**
+ * {@link IValue} implementation to work with Integer valued {@link ITimeValue}
+ * objects
+ * 
+ * @author martin_smock
+ */
+public class IntegerValue implements IValue<Integer> {
+
+	public static final IntegerValue NEUTRAL = new IntegerValue(0);
+
+	private Integer value;
+
+	public IntegerValue(Integer value) {
+		this.value = value;
+	}
+
+	public IntegerValue(int value) {
+		this.value = Integer.valueOf(value);
+	}
+
+	public IntegerValue(String valueAsString) throws NumberFormatException {
+		this.value = Integer.parseInt(valueAsString);
+	}
+
+	@Override
+	public IntegerValue add(Integer o) {
+		value += o;
+		return this;
+	}
+
+	@Override
+	public boolean matches(IValue<Integer> other) {
+		return this.value.equals(other.getValue());
+	}
+
+	@Override
+	public Integer getValue() {
+		return value;
+	}
+
+	@Override
+	public IntegerValue getInverse() {
+		return new IntegerValue(-getValue());
+	}
+
+	@Override
+	public String toString() {
+		return "IntegerValue [value=" + value + "]";
+	}
+
+	@Override
+	public IntegerValue getCopy() {
+		return new IntegerValue(value);
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + ((value == null) ? 0 : value.hashCode());
+		return result;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		IntegerValue other = (IntegerValue) obj;
+		if (value == null) {
+			if (other.value != null)
+				return false;
+		} else if (!value.equals(other.value))
+			return false;
+		return true;
+	}
+
+}
diff --git a/src/main/java/li/strolch/model/timevalue/impl/StringSetValue.java b/src/main/java/li/strolch/model/timevalue/impl/StringSetValue.java
new file mode 100644
index 000000000..499211bfc
--- /dev/null
+++ b/src/main/java/li/strolch/model/timevalue/impl/StringSetValue.java
@@ -0,0 +1,86 @@
+package li.strolch.model.timevalue.impl;
+
+import java.util.HashSet;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.Set;
+
+import li.strolch.model.timevalue.ITimeValue;
+import li.strolch.model.timevalue.IValue;
+
+
+/**
+ * {@link IValue} implementation to work with String valued {@link ITimeValue}
+ * objects. Since a java.util.String object does not define a inverse, a
+ * algebraic {@link AString} wrapper is used.
+ * 
+ * @author martin_smock
+ */
+public class StringSetValue implements IValue<Set<AString>> {
+
+	private static Set<AString> neu = Collections.emptySet();
+	public static final IValue<Set<AString>> NEUTRAL = new StringSetValue(neu);
+
+	private Set<AString> aStrings = new HashSet<AString>();
+
+	public StringSetValue() {
+	}
+
+	public StringSetValue(final Set<AString> aStrings) {
+		this.aStrings = aStrings;
+	}
+
+	@Override
+	public Set<AString> getValue() {
+		return aStrings;
+	}
+
+	@Override
+	public IValue<Set<AString>> add(Set<AString> o) {
+
+		Set<AString> toBeAdded = new HashSet<AString>(o);
+
+		for (Iterator<AString> iter1 = toBeAdded.iterator(); iter1.hasNext();) {
+			AString toAdd = iter1.next();
+			for (Iterator<AString> iter = aStrings.iterator(); iter.hasNext();) {
+				AString aString = iter.next();
+				boolean valueMatch = aString.getString().equals(toAdd.getString());
+				boolean compensate = (toAdd.isInverse() && !aString.isInverse())
+						|| (!toAdd.isInverse() && aString.isInverse());
+				if (valueMatch && compensate) {
+					iter.remove();
+					iter1.remove();
+				}
+			}
+		}
+		aStrings.addAll(toBeAdded);
+		return this;
+	}
+
+	@Override
+	public boolean matches(IValue<Set<AString>> other) {
+		return this.getValue().equals(other.getValue());
+	}
+
+	@Override
+	public IValue<Set<AString>> getInverse() {
+		Set<AString> inverseSet = new HashSet<AString>();
+		for (AString as : aStrings) {
+			inverseSet.add(as.getInverse());
+		}
+		StringSetValue inverse = new StringSetValue();
+		inverse.aStrings = inverseSet;
+		return inverse;
+	}
+
+	@Override
+	public StringSetValue getCopy() {
+		return new StringSetValue(aStrings);
+	}
+
+	@Override
+	public String toString() {
+		return "StringSetValue [aStrings=" + aStrings + "]";
+	}
+
+}
diff --git a/src/main/java/li/strolch/model/timevalue/impl/TimeValue.java b/src/main/java/li/strolch/model/timevalue/impl/TimeValue.java
new file mode 100644
index 000000000..bd14fed55
--- /dev/null
+++ b/src/main/java/li/strolch/model/timevalue/impl/TimeValue.java
@@ -0,0 +1,90 @@
+package li.strolch.model.timevalue.impl;
+
+import li.strolch.model.timevalue.ITimeValue;
+import li.strolch.model.timevalue.IValue;
+
+/**
+ * @author martin_smock
+ */
+@SuppressWarnings("rawtypes")
+public class TimeValue<T extends IValue> implements ITimeValue <T> {
+	
+	protected final Long time; 
+	protected T value; 
+	
+	/**
+	 * @param time
+	 * @param value
+	 */
+	public TimeValue(final Long time, final T value){
+		this.time = time; 
+		this.value = value; 
+	}
+
+	@Override
+	@SuppressWarnings("unchecked")
+	public T getValue() {
+		return (T) value.getCopy();
+	}
+
+	@Override
+	public Long getTime() {
+		return time;
+	}
+
+	@Override
+	public ITimeValue<T> setValue(final T value) {
+		this.value = value;
+		return this; 
+	}
+
+	@SuppressWarnings("unchecked")
+	@Override
+	public ITimeValue<T> add(final T change) {
+		this.value.add(change.getValue()); 
+		return this; 
+	}
+	
+	@Override
+	public int compareTo(final ITimeValue<T> arg0) {
+		return this.getTime().compareTo(arg0.getTime());
+	}
+
+	@Override
+	public String toString() {
+		return "TimeValue [time=" + time + ", value=" + value + "]";
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + ((time == null) ? 0 : time.hashCode());
+		result = prime * result + ((value == null) ? 0 : value.hashCode());
+		return result;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		@SuppressWarnings("unchecked")
+		TimeValue<T> other = (TimeValue<T>) obj;
+		if (time == null) {
+			if (other.time != null)
+				return false;
+		} else if (!time.equals(other.time))
+			return false;
+		if (value == null) {
+			if (other.value != null)
+				return false;
+		} else if (!value.equals(other.value))
+			return false;
+		return true;
+	}
+	
+}
diff --git a/src/main/java/li/strolch/model/timevalue/impl/TimeVariable.java b/src/main/java/li/strolch/model/timevalue/impl/TimeVariable.java
new file mode 100644
index 000000000..43a71c63f
--- /dev/null
+++ b/src/main/java/li/strolch/model/timevalue/impl/TimeVariable.java
@@ -0,0 +1,98 @@
+package li.strolch.model.timevalue.impl;
+
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.SortedSet;
+import java.util.TreeSet;
+
+import li.strolch.model.timevalue.ITimeValue;
+import li.strolch.model.timevalue.ITimeVariable;
+import li.strolch.model.timevalue.IValue;
+import li.strolch.model.timevalue.IValueChange;
+
+
+/**
+ * @author martin_smock
+ */
+@SuppressWarnings("rawtypes")
+public class TimeVariable<T extends IValue> implements ITimeVariable<T> {
+
+	public SortedSet<ITimeValue<T>> container = new TreeSet<ITimeValue<T>>();
+
+	@Override
+	public ITimeValue<T> getValueAt(final Long time) {
+		ITimeValue<T> tmp = null;
+		for (ITimeValue<T> value : container) {
+			if (value.getTime() <= time) {
+				tmp = value;
+			} else {
+				break;
+			}
+		}
+		return tmp;
+	}
+
+	@Override
+	public void setValueAt(final Long time, final T targetValue) {
+		ITimeValue<T> current = getValueAt(time);
+		if (current != null && current.getTime().equals(time)) {
+			current.setValue(targetValue);
+		} else {
+			container.add(new TimeValue<T>(time, targetValue));
+		}
+	}
+
+	@Override
+	public SortedSet<ITimeValue<T>> getFutureValues(final Long time) {
+		TimeValue<T> picker = new TimeValue<T>(time, null);
+		return new TreeSet<ITimeValue<T>>(container.tailSet(picker));
+	}
+
+	@Override
+	public Collection<ITimeValue<T>> getPastValues(final Long time) {
+		TimeValue<T> picker = new TimeValue<T>(time, null);
+		return new TreeSet<ITimeValue<T>>(container.headSet(picker));
+	}
+
+	@Override
+	public void applyChange(final IValueChange<T> change) {
+
+		SortedSet<ITimeValue<T>> futureValues = getFutureValues(change.getTime());
+		for (ITimeValue<T> value : futureValues) {
+			value.add(change.getValue());
+		}
+
+		ITimeValue<T> initialValue = getValueAt(change.getTime());
+		if (initialValue == null) {
+			ITimeValue<T> newValue = new TimeValue<T>(change.getTime(), change.getValue());
+			container.add(newValue);
+		} else if (initialValue.getTime().longValue() < change.getTime().longValue()) {
+			ITimeValue<T> newValue = new TimeValue<T>(change.getTime(), initialValue.getValue());
+			newValue.add(change.getValue()); 
+			container.add(newValue);
+		}
+		compact();
+	}
+
+	@SuppressWarnings("unchecked")
+	@Override
+	public void compact() {
+
+		if (container.size() < 2)
+			return;
+
+		Iterator<ITimeValue<T>> iterator = container.iterator();
+		ITimeValue<T> predecessor = iterator.next();
+
+		while (iterator.hasNext()) {
+			ITimeValue<T> successor = iterator.next();
+			if (successor.getValue().matches(predecessor.getValue())) {
+				iterator.remove();
+			} else {
+				predecessor = successor;
+			}
+		}
+
+	}
+
+}
diff --git a/src/main/java/li/strolch/model/timevalue/impl/ValueChange.java b/src/main/java/li/strolch/model/timevalue/impl/ValueChange.java
new file mode 100644
index 000000000..8d7d33664
--- /dev/null
+++ b/src/main/java/li/strolch/model/timevalue/impl/ValueChange.java
@@ -0,0 +1,77 @@
+package li.strolch.model.timevalue.impl;
+
+import li.strolch.model.timevalue.IValue;
+import li.strolch.model.timevalue.IValueChange;
+
+/**
+ * @author martin_smock
+ */
+@SuppressWarnings("rawtypes")
+public class ValueChange<T extends IValue> implements IValueChange<T> {
+
+	protected final Long time;
+	protected final T value;
+
+	/**
+	 * @param time
+	 * @param value
+	 */
+	public ValueChange(final Long time, final T value) {
+		this.time = time;
+		this.value = value;
+	}
+
+	@Override
+	public Long getTime() {
+		return time;
+	}
+
+	@Override
+	@SuppressWarnings("unchecked")
+	public T getValue() {
+		return (T) value.getCopy();
+	}
+
+	@Override
+	@SuppressWarnings("unchecked")
+	public IValueChange<T> getInverse() {
+		return new ValueChange(time, value.getInverse());
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		ValueChange<?> other = (ValueChange<?>) obj;
+		if (time == null) {
+			if (other.time != null)
+				return false;
+		} else if (!time.equals(other.time))
+			return false;
+		if (value == null) {
+			if (other.value != null)
+				return false;
+		} else if (!value.equals(other.value))
+			return false;
+		return true;
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + ((time == null) ? 0 : time.hashCode());
+		result = prime * result + ((value == null) ? 0 : value.hashCode());
+		return result;
+	}
+
+	@Override
+	public String toString() {
+		return "ValueChange [time=" + time + ", value=" + value + "]";
+	}
+
+}
diff --git a/src/test/java/li/strolch/model/timedstate/TimeStateTest.java b/src/test/java/li/strolch/model/timedstate/TimeStateTest.java
new file mode 100644
index 000000000..f2525094c
--- /dev/null
+++ b/src/test/java/li/strolch/model/timedstate/TimeStateTest.java
@@ -0,0 +1,96 @@
+package li.strolch.model.timedstate;
+
+import junit.framework.Assert;
+import li.strolch.model.timedstate.ITimedState;
+import li.strolch.model.timedstate.TimedState;
+import li.strolch.model.timevalue.ITimeValue;
+import li.strolch.model.timevalue.IValueChange;
+import li.strolch.model.timevalue.impl.DoubleValue;
+import li.strolch.model.timevalue.impl.ValueChange;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class TimeStateTest {
+
+	private ITimedState<DoubleValue> state = new TimedState<DoubleValue>();
+
+	final DoubleValue expectedValue1 = new DoubleValue(Double.valueOf(100D));
+	final DoubleValue expectedValue2 = new DoubleValue(Double.valueOf(200D));
+
+	final Long t0 = Long.valueOf(0);
+	final Long t10 = Long.valueOf(10);
+	final Long t20 = Long.valueOf(20);
+	final Long t30 = Long.valueOf(30);
+	final Long t100 = Long.valueOf(100);
+
+	@Before
+	public void before() {
+
+		final IValueChange<DoubleValue> change1 = new ValueChange<DoubleValue>(t10, expectedValue1);
+		state.applyChange(change1);
+
+		final ITimeValue<DoubleValue> stateAt9 = state.getStateAt(9L);
+		Assert.assertNull(stateAt9);
+
+		final ITimeValue<DoubleValue> stateAt11 = state.getStateAt(11L);
+		Assert.assertNotNull(stateAt11);
+		Assert.assertEquals(true, stateAt11.getValue().matches(expectedValue1));
+
+		final IValueChange<DoubleValue> change2 = new ValueChange<DoubleValue>(t30, expectedValue1);
+		state.applyChange(change2);
+
+		final ITimeValue<DoubleValue> stateAt31 = state.getStateAt(31L);
+		Assert.assertNotNull(stateAt31);
+		Assert.assertEquals(true, stateAt31.getValue().matches(expectedValue2));
+	}
+
+	@Test
+	public void testGetNextMatch() {
+
+		ITimeValue<DoubleValue> nextMatch = state.getNextMatch(t0, expectedValue1);
+		Assert.assertNotNull(nextMatch);
+		Assert.assertEquals(t10, nextMatch.getTime());
+
+		nextMatch = state.getNextMatch(t20, expectedValue1);
+		Assert.assertNull(nextMatch);
+
+		nextMatch = state.getNextMatch(t20, expectedValue2);
+		Assert.assertNotNull(nextMatch);
+		Assert.assertEquals(t30, nextMatch.getTime());
+
+		nextMatch = state.getNextMatch(t30, expectedValue2);
+		Assert.assertNotNull(nextMatch);
+		Assert.assertEquals(t30, nextMatch.getTime());
+
+		nextMatch = state.getNextMatch(t100, expectedValue1);
+		Assert.assertNull(nextMatch);
+
+		nextMatch = state.getNextMatch(t100, expectedValue2);
+		Assert.assertNull(nextMatch);
+
+	}
+
+	@Test
+	public void testGetPreviousMatch() {
+
+		ITimeValue<DoubleValue> previousMatch = state.getPreviousMatch(t100, expectedValue2);
+		Assert.assertNotNull(previousMatch);
+		Assert.assertEquals(t30, previousMatch.getTime());
+
+		previousMatch = state.getPreviousMatch(t30, expectedValue2);
+		Assert.assertNull(previousMatch);
+		
+		previousMatch = state.getPreviousMatch(t20, expectedValue2);
+		Assert.assertNull(previousMatch);
+		
+		previousMatch = state.getPreviousMatch(t20, expectedValue1);
+		Assert.assertNotNull(previousMatch);
+		Assert.assertEquals(t10, previousMatch.getTime());
+		
+		previousMatch = state.getPreviousMatch(t10, expectedValue1);
+		Assert.assertNull(previousMatch);
+
+	}
+
+}
diff --git a/src/test/java/li/strolch/model/timevalue/FloatTimeVariableTest.java b/src/test/java/li/strolch/model/timevalue/FloatTimeVariableTest.java
new file mode 100644
index 000000000..e8fe45670
--- /dev/null
+++ b/src/test/java/li/strolch/model/timevalue/FloatTimeVariableTest.java
@@ -0,0 +1,137 @@
+package li.strolch.model.timevalue;
+
+import java.util.Collection;
+import java.util.SortedSet;
+
+import junit.framework.Assert;
+import li.strolch.model.timevalue.ITimeValue;
+import li.strolch.model.timevalue.IValue;
+import li.strolch.model.timevalue.IValueChange;
+import li.strolch.model.timevalue.impl.DoubleValue;
+import li.strolch.model.timevalue.impl.TimeVariable;
+import li.strolch.model.timevalue.impl.ValueChange;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class FloatTimeVariableTest {
+
+	private static final Long MAX = 100L;
+	private static final Long STEP = 10L;
+	private static final Long PICK = 50L;
+
+	private TimeVariable<DoubleValue> timeVariable;
+
+	/**
+	 * set the values ascending with a difference of STEP
+	 */
+	@Before
+	public void init() {
+		timeVariable = new TimeVariable<DoubleValue>();
+		for (long i = 0; i < MAX; i += STEP) {
+			timeVariable.setValueAt(Long.valueOf(i), new DoubleValue(i));
+		}
+	}
+
+	@Test
+	public void testGetValueAt() {
+		ITimeValue<DoubleValue> valueAt = timeVariable.getValueAt(PICK);
+		Assert.assertEquals(PICK.doubleValue(), valueAt.getValue().getValue());
+	}
+
+	/**
+	 * test, that the future values start with the PICK time and are ascending
+	 */
+	@Test
+	public void testGetFutureValues() {
+		Collection<ITimeValue<DoubleValue>> futureValues = timeVariable.getFutureValues(PICK);
+		Long expectedTime = PICK;
+		Double expectedValue = PICK.doubleValue();
+		for (ITimeValue<DoubleValue> value : futureValues) {
+			Assert.assertEquals(expectedTime, value.getTime());
+			Assert.assertTrue(value.getValue().matches(new DoubleValue(expectedValue)));
+			expectedTime += STEP;
+			expectedValue += STEP.doubleValue();
+		}
+	}
+
+	/**
+	 * test, that the past values time fields start with 0 and are strictly
+	 * smaller than PICK
+	 */
+	@Test
+	public void testGetPastValues() {
+		Collection<ITimeValue<DoubleValue>> pastValues = timeVariable.getPastValues(MAX);
+		Long expectedTime = 0L;
+		Double expectedValue = expectedTime.doubleValue();
+		for (ITimeValue<DoubleValue> value : pastValues) {
+			Assert.assertEquals(expectedTime, value.getTime());
+			Assert.assertTrue(value.getValue().matches(new DoubleValue(expectedValue)));
+			expectedTime += STEP;
+			expectedValue += STEP.doubleValue();
+		}
+	}
+
+	/**
+	 * apply a change and check that the future values are all changed
+	 */
+	@Test
+	public void testApplyChange() {
+
+		DoubleValue doubleValue = new DoubleValue(STEP.doubleValue());
+
+		IValueChange<DoubleValue> change = new ValueChange<DoubleValue>(PICK, doubleValue);
+		timeVariable.applyChange(change);
+
+		Collection<ITimeValue<DoubleValue>> futureValues = timeVariable.getFutureValues(PICK);
+		Long expectedTime = PICK;
+
+		IValue<Double> expectedValue = new DoubleValue(PICK.doubleValue() + change.getValue().getValue());
+
+		for (ITimeValue<DoubleValue> value : futureValues) {
+			Assert.assertEquals(expectedTime, value.getTime());
+			Assert.assertTrue(expectedValue.matches(value.getValue()));
+			expectedTime += STEP;
+			expectedValue = expectedValue.add(STEP.doubleValue());
+		}
+	}
+
+	/**
+	 * apply a change to an empty time variable
+	 */
+	@Test
+	public void testApply2Change() {
+
+		timeVariable = new TimeVariable<DoubleValue>();
+
+		DoubleValue doubleValue = new DoubleValue(STEP.doubleValue());
+
+		IValueChange<DoubleValue> change = new ValueChange<DoubleValue>(PICK, doubleValue);
+		timeVariable.applyChange(change);
+
+		ITimeValue<DoubleValue> actual = timeVariable.getValueAt(PICK); 
+		Assert.assertNotNull(actual); 	
+		
+		IValue<Double> expectedValue = new DoubleValue(STEP.doubleValue());
+		Assert.assertEquals(true, actual.getValue().matches(expectedValue));
+	}
+
+	/**
+	 * test that successors matching the values of their predecessors are
+	 * removed
+	 */
+	@Test
+	public void testCompact() {
+
+		timeVariable = new TimeVariable<DoubleValue>();
+		for (Long i = 0L; i < MAX; i += STEP) {
+			timeVariable.setValueAt(i, new DoubleValue(STEP.doubleValue()));
+		}
+		// call
+		timeVariable.compact();
+		// check
+		SortedSet<ITimeValue<DoubleValue>> futureValues = timeVariable.getFutureValues(0L);
+		Assert.assertEquals(1, futureValues.size());
+	}
+
+}
diff --git a/src/test/java/li/strolch/model/timevalue/IntegerTimeVariableTest.java b/src/test/java/li/strolch/model/timevalue/IntegerTimeVariableTest.java
new file mode 100644
index 000000000..9af523bb1
--- /dev/null
+++ b/src/test/java/li/strolch/model/timevalue/IntegerTimeVariableTest.java
@@ -0,0 +1,131 @@
+package li.strolch.model.timevalue;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.SortedSet;
+
+import junit.framework.Assert;
+import li.strolch.model.timevalue.ITimeValue;
+import li.strolch.model.timevalue.IValue;
+import li.strolch.model.timevalue.IValueChange;
+import li.strolch.model.timevalue.impl.IntegerValue;
+import li.strolch.model.timevalue.impl.TimeVariable;
+import li.strolch.model.timevalue.impl.ValueChange;
+
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * Basic tests for a {@link TimeVariable} with integer values.
+ * 
+ * @author martin_smock
+ */
+public class IntegerTimeVariableTest {
+
+	private static final Long MAX = 100L;
+	private static final Integer STEP = 10;
+	private static final Long PICK = 50L;
+
+	private TimeVariable<IntegerValue> timeVariable;
+	private Map<Long, IntegerValue> expectedValues = new HashMap<Long, IntegerValue>();
+
+	/**
+	 * set the values ascending with a difference of STEP
+	 */
+	@Before
+	public void init() {
+		timeVariable = new TimeVariable<IntegerValue>();
+		for (int i = 0; i < MAX; i += STEP) {
+			IntegerValue expectedValue = new IntegerValue(i);
+			Long time = Long.valueOf(i);
+			expectedValues.put(time, expectedValue);
+			timeVariable.setValueAt(time, expectedValue);
+		}
+	}
+
+	@Test
+	public void testGetValueAt() {
+		ITimeValue<IntegerValue> valueAt = timeVariable.getValueAt(PICK);
+		Assert.assertEquals(expectedValues.get(PICK), valueAt.getValue());
+	}
+
+	/**
+	 * test, that the future values start with the PICK time and are ascending
+	 */
+	@Test
+	public void testGetFutureValues() {
+		Collection<ITimeValue<IntegerValue>> futureValues = timeVariable.getFutureValues(PICK);
+		Long expectedTime = PICK;
+		Integer expectedValue = PICK.intValue();
+		for (ITimeValue<IntegerValue> value : futureValues) {
+			Assert.assertEquals(expectedTime, value.getTime());
+			Assert.assertTrue(value.getValue().matches(new IntegerValue(expectedValue)));
+			expectedTime += STEP;
+			expectedValue += STEP.intValue();
+		}
+	}
+
+	/**
+	 * test, that the past values time fields start with 0 and are strictly
+	 * smaller than PICK
+	 */
+	@Test
+	public void testGetPastValues() {
+		Collection<ITimeValue<IntegerValue>> pastValues = timeVariable.getPastValues(MAX);
+		Long expectedTime = 0L;
+		Integer expectedValue = expectedTime.intValue();
+		for (ITimeValue<IntegerValue> value : pastValues) {
+			Assert.assertEquals(expectedTime, value.getTime());
+			Assert.assertTrue(value.getValue().matches(new IntegerValue(expectedValue)));
+			expectedTime += STEP;
+			expectedValue += STEP.intValue();
+		}
+	}
+
+	/**
+	 * apply a change and check that the future values are all changed
+	 */
+	@Test
+	public void testApplyChange() {
+
+		IntegerValue integerValue = new IntegerValue(STEP.intValue());
+
+		IValueChange<IntegerValue> change = new ValueChange<IntegerValue>(PICK, integerValue);
+		timeVariable.applyChange(change);
+
+		Collection<ITimeValue<IntegerValue>> futureValues = timeVariable.getFutureValues(PICK);
+		Long expectedTime = PICK;
+
+		IValue<Integer> expectedValue = new IntegerValue(PICK.intValue() + change.getValue().getValue());
+		for (ITimeValue<IntegerValue> value : futureValues) {
+			Assert.assertEquals(expectedTime, value.getTime());
+			Assert.assertTrue(expectedValue.matches(value.getValue()));
+			expectedTime += STEP;
+			expectedValue = expectedValue.add(STEP.intValue());
+		}
+	}
+
+	/**
+	 * test that successors matching the values of their predecessors are
+	 * removed
+	 */
+	@Test
+	public void testCompact() {
+		timeVariable = new TimeVariable<IntegerValue>();
+		for (Long i = 0L; i < MAX; i += STEP) {
+			timeVariable.setValueAt(i, new IntegerValue(STEP.intValue()));
+		}
+
+		// call
+		timeVariable.compact();
+
+		// check
+		SortedSet<ITimeValue<IntegerValue>> futureValues = timeVariable.getFutureValues(0L);
+		Assert.assertEquals(1, futureValues.size());
+
+		ITimeValue<IntegerValue> next = futureValues.iterator().next();
+		Assert.assertEquals(Long.valueOf(0), next.getTime());
+	}
+
+}
diff --git a/src/test/java/li/strolch/model/timevalue/StringTimeVariableTest.java b/src/test/java/li/strolch/model/timevalue/StringTimeVariableTest.java
new file mode 100644
index 000000000..031d2de0e
--- /dev/null
+++ b/src/test/java/li/strolch/model/timevalue/StringTimeVariableTest.java
@@ -0,0 +1,118 @@
+package li.strolch.model.timevalue;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.SortedSet;
+
+import junit.framework.Assert;
+import li.strolch.model.timevalue.ITimeValue;
+import li.strolch.model.timevalue.IValue;
+import li.strolch.model.timevalue.IValueChange;
+import li.strolch.model.timevalue.impl.AString;
+import li.strolch.model.timevalue.impl.StringSetValue;
+import li.strolch.model.timevalue.impl.TimeVariable;
+import li.strolch.model.timevalue.impl.ValueChange;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class StringTimeVariableTest {
+
+	private static final Long MAX = 100L;
+	private static final Long STEP = 10L;
+	private static final Long PICK = 50L;
+
+	private TimeVariable<IValue<Set<AString>>> timeVariable;
+
+	private Map<Long, StringSetValue> testSets = new HashMap<Long, StringSetValue>();
+
+	@Before
+	public void init() {
+		timeVariable = new TimeVariable<IValue<Set<AString>>>();
+		for (Long i = 0L; i < MAX; i += STEP) {
+			Set<AString> testSet = new HashSet<AString>();
+			StringSetValue testValue = new StringSetValue(testSet);
+			testSets.put(i, testValue);
+			testSet.add(new AString("string " + i));
+			timeVariable.setValueAt(i, new StringSetValue(testSet));
+		}
+	}
+
+	@Test
+	public void testGetValueAt() {
+		ITimeValue<IValue<Set<AString>>> valueAt = timeVariable.getValueAt(PICK);
+		Assert.assertEquals(true, valueAt.getValue().matches(testSets.get(PICK)));
+	}
+
+	@Test
+	public void testGetFutureValues() {
+		Collection<ITimeValue<IValue<Set<AString>>>> futureValues = timeVariable.getFutureValues(PICK);
+		for (ITimeValue<IValue<Set<AString>>> iTimeValue : futureValues) {
+			Long time = iTimeValue.getTime();
+			Assert.assertEquals(true, time >= PICK);
+			Assert.assertNotNull(iTimeValue.getValue());
+			Assert.assertEquals(true, iTimeValue.getValue().matches(testSets.get(time)));
+		}
+	}
+
+	@Test
+	public void testGetPastValues() {
+		Collection<ITimeValue<IValue<Set<AString>>>> pastValues = timeVariable.getPastValues(PICK);
+		for (ITimeValue<IValue<Set<AString>>> iTimeValue : pastValues) {
+			Long time = iTimeValue.getTime();
+			Assert.assertEquals(true, time < PICK);
+			Assert.assertNotNull(iTimeValue.getValue());
+			Assert.assertEquals(true, iTimeValue.getValue().matches(testSets.get(time)));
+		}
+	}
+
+	@Test
+	public void testApplyChange() {
+
+		Set<AString> testSet = new HashSet<AString>();
+		testSet.add(new AString("Martin"));
+		StringSetValue testValue = new StringSetValue(testSet);
+
+		timeVariable = new TimeVariable<IValue<Set<AString>>>();
+		timeVariable.setValueAt(PICK, testValue);
+
+		IValue<Set<AString>> inverseTestValue = testValue.getInverse();
+		IValueChange<IValue<Set<AString>>> change = new ValueChange<IValue<Set<AString>>>(PICK, inverseTestValue);
+		timeVariable.applyChange(change);
+
+		// check the future values
+		Collection<ITimeValue<IValue<Set<AString>>>> futureValues = timeVariable.getFutureValues(0L);
+		for (ITimeValue<IValue<Set<AString>>> iTimeValue : futureValues) {
+			System.out.println("++ " + iTimeValue);
+		}
+		
+		Assert.assertEquals(1, futureValues.size()); // a empty one is left
+
+	}
+
+	@Test
+	public void testCompact() {
+
+		timeVariable = new TimeVariable<IValue<Set<AString>>>();
+		for (Long i = 0L; i < MAX; i += STEP) {
+			Set<AString> testSet = new HashSet<AString>();
+			StringSetValue testValue = new StringSetValue(testSet);
+			testSets.put(i, testValue);
+			testSet.add(new AString("same string"));
+			timeVariable.setValueAt(i, new StringSetValue(testSet));
+		}
+
+		SortedSet<ITimeValue<IValue<Set<AString>>>> valuesInitial = timeVariable.getFutureValues(0L);
+		Assert.assertEquals(true, valuesInitial.size() > 1);
+
+		timeVariable.compact();
+
+		SortedSet<ITimeValue<IValue<Set<AString>>>> valuesCompacted = timeVariable.getFutureValues(0L);
+		Assert.assertEquals(1, valuesCompacted.size());
+
+	}
+
+}
diff --git a/src/test/java/li/strolch/model/timevalue/ValueTests.java b/src/test/java/li/strolch/model/timevalue/ValueTests.java
new file mode 100644
index 000000000..072262fe6
--- /dev/null
+++ b/src/test/java/li/strolch/model/timevalue/ValueTests.java
@@ -0,0 +1,81 @@
+package li.strolch.model.timevalue;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import li.strolch.model.timevalue.IValue;
+import li.strolch.model.timevalue.impl.AString;
+import li.strolch.model.timevalue.impl.DoubleValue;
+import li.strolch.model.timevalue.impl.IntegerValue;
+import li.strolch.model.timevalue.impl.StringSetValue;
+
+import org.junit.Test;
+
+public class ValueTests {
+
+	/**
+	 * check, that adding the inverse results in the neutral element (=0)
+	 */
+	@Test
+	public void testDoubleInverse() {
+		DoubleValue value = new DoubleValue(10.0d);
+		DoubleValue inverse = value.getInverse();
+		assertEquals(Double.valueOf(-10.0d), inverse.getValue());
+		assertEquals(Double.valueOf(0), value.add(inverse.getValue())
+				.getValue());
+	}
+	
+	/**
+	 * check, that adding the inverse results in the neutral element (=0)
+	 */
+	@Test
+	public void testIntegerInverse() {
+		IntegerValue value = new IntegerValue(10);
+		IntegerValue inverse = value.getInverse();
+		assertEquals(Integer.valueOf(-10), inverse.getValue());
+		assertEquals(Integer.valueOf(0), value.add(inverse.getValue())
+				.getValue());
+	}
+
+	/**
+	 * check, that adding the inverse results in the neutral element (empty Set)
+	 */
+	@Test
+	public void testStringSetInverse() {
+		Set<AString> aStrings = new HashSet<AString>();
+		for (int i = 0; i < 10; i++) {
+			aStrings.add(new AString("string " + i));
+		}
+		IValue<Set<AString>> value = new StringSetValue(aStrings);
+		IValue<Set<AString>> inverse = value.getInverse();
+		assertEquals(true, value.matches(inverse.getInverse()));
+		assertEquals(0, value.add(inverse.getValue()).getValue().size());
+	}
+
+	/**
+	 * check, that the difference left is as expected
+	 */
+	@Test
+	public void testStringSetNearInverse() {
+
+		Set<AString> aStrings1 = new HashSet<AString>();
+		for (int i = 0; i < 10; i++) {
+			aStrings1.add(new AString("string " + i));
+		}
+		IValue<Set<AString>> value1 = new StringSetValue(aStrings1);
+
+		Set<AString> aStrings2 = new HashSet<AString>();
+		for (int i = 0; i < 9; i++) {
+			aStrings2.add(new AString("string " + i, true));
+		}
+		IValue<Set<AString>> value2 = new StringSetValue(aStrings2);
+
+		assertEquals(false, value1.matches(value2));
+		assertEquals(1, value1.add(value2.getValue()).getValue().size());
+		assertEquals(10, value1.add(value2.getInverse().getValue()).getValue()
+				.size());
+	}
+
+}