diff --git a/bin/test/uebung/uebung09/collection/SetTest.class b/bin/test/uebung/uebung09/collection/SetTest.class
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index 0000000..1aa1f92
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diff --git a/bin/uebung07/quantities/plain/Length.class b/bin/uebung07/quantities/plain/Length.class
deleted file mode 100644
index 028c707..0000000
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diff --git a/bin/uebung07/quantities/plain/LengthUnit.class b/bin/uebung07/quantities/plain/LengthUnit.class
deleted file mode 100644
index f51a92f..0000000
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diff --git a/bin/uebung07/quantities/plain/PlainQuantitiesDemo.class b/bin/uebung07/quantities/plain/PlainQuantitiesDemo.class
deleted file mode 100644
index df63b4d..0000000
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diff --git a/bin/uebung07/quantities/plain/Quantity.class b/bin/uebung07/quantities/plain/Quantity.class
deleted file mode 100644
index 503cd51..0000000
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diff --git a/bin/uebung07/quantities/plain/Time.class b/bin/uebung07/quantities/plain/Time.class
deleted file mode 100644
index 73a6f04..0000000
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diff --git a/bin/uebung07/quantities/plain/Unit.class b/bin/uebung07/quantities/plain/Unit.class
deleted file mode 100644
index ddea055..0000000
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diff --git a/bin/uebung09/collection/BigSet$1.class b/bin/uebung09/collection/BigSet$1.class
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index 15c139e..4762368 100644
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diff --git a/bin/uebung09/collection/SingeltonSet$1.class b/bin/uebung09/collection/SingeltonSet$1.class
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index 0000000..427fab0
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new file mode 100644
index 0000000..8624d52
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diff --git a/bin/uebung10/logo/BlackForest.class b/bin/uebung10/logo/BlackForest.class
new file mode 100644
index 0000000..14b9deb
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diff --git a/bin/uebung10/logo/HanselGretelTest.class b/bin/uebung10/logo/HanselGretelTest.class
index 36adb1b..bec3a7b 100644
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diff --git a/bin/uebung10/logo/HanselGretelVisitor$1.class b/bin/uebung10/logo/HanselGretelVisitor$1.class
index 5daac03..2236119 100644
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diff --git a/bin/uebung10/logo/HanselGretelVisitor$2.class b/bin/uebung10/logo/HanselGretelVisitor$2.class
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diff --git a/bin/uebung10/logo/HanselGretelVisitor$3.class b/bin/uebung10/logo/HanselGretelVisitor$3.class
new file mode 100644
index 0000000..52ceb07
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diff --git a/bin/uebung10/logo/HanselGretelVisitor$DownState.class b/bin/uebung10/logo/HanselGretelVisitor$DownState.class
deleted file mode 100644
index 23584b2..0000000
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diff --git a/bin/uebung10/logo/HanselGretelVisitor$ShortUpState.class b/bin/uebung10/logo/HanselGretelVisitor$ShortUpState.class
deleted file mode 100644
index ba642a7..0000000
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diff --git a/bin/uebung10/logo/HanselGretelVisitor$State.class b/bin/uebung10/logo/HanselGretelVisitor$State.class
index 823ded1..8dbdd87 100644
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diff --git a/bin/uebung10/logo/HanselGretelVisitor.class b/bin/uebung10/logo/HanselGretelVisitor.class
index 5a1d894..c04b278 100644
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diff --git a/src/uebung07/quantities/plain/Length.java b/src/uebung07/quantities/plain/Length.java
deleted file mode 100644
index 5efacf3..0000000
--- a/src/uebung07/quantities/plain/Length.java
+++ /dev/null
@@ -1,46 +0,0 @@
-package uebung07.quantities.plain;
-
-import static uebung07.quantities.plain.LengthUnit.METER;
-import static uebung07.quantities.plain.TimeUnit.SECOND;
-import static uebung07.quantities.plain.VelocityUnit.METER_PER_SECOND;
-
-public class Length extends Quantity {
-    private final LengthUnit unit;
-
-    public Length(double value, LengthUnit unit) {
-        super(value, unit);
-        this.unit = unit;
-    }
-
-    public Length plus(Length other) {
-        return new Length(value + other.getBaseValue() / unit.baseFactor, unit);
-    }
-
-    public Length minus(Length other) {
-        return new Length(value - other.getBaseValue() / unit.baseFactor, unit);
-    }
-
-    public Length mult(double f) {
-        return new Length(value * f, unit);
-    }
-
-    public Length div(double f) {
-        return new Length(value / f, unit);
-    }
-
-    public Length to(LengthUnit unit) {
-        return new Length(getBaseValue() / unit.baseFactor, unit);
-    }
-
-    public double div(Length other) {
-        return getBaseValue() / other.getBaseValue();
-    }
-
-    public Velocity div(Time t) {
-        return new Velocity(this.value(METER) / t.value(SECOND), METER_PER_SECOND);
-    }
-
-    public Time div(Velocity v) {
-        return new Time(this.value(METER) / v.value(METER_PER_SECOND), SECOND);
-    }
-}
diff --git a/src/uebung07/quantities/plain/LengthUnit.java b/src/uebung07/quantities/plain/LengthUnit.java
deleted file mode 100644
index c98102b..0000000
--- a/src/uebung07/quantities/plain/LengthUnit.java
+++ /dev/null
@@ -1,14 +0,0 @@
-package uebung07.quantities.plain;
-
-public class LengthUnit extends Unit {
-    public LengthUnit(String name, double baseFactor) {
-        super(name, baseFactor);
-    }
-
-    public static final LengthUnit METER = new LengthUnit("m", 1);
-    public static final LengthUnit MILLIMETER = new LengthUnit("mm", 0.001);
-    public static final LengthUnit KILOMETER = new LengthUnit("km", 1000);
-    public static final LengthUnit MILE = new LengthUnit("mi", 1609.344);
-    public static final LengthUnit LIGHTYEAR = new LengthUnit("ly", 9460730472580800.0);
-    public static final LengthUnit PARSEC = new LengthUnit("pc", 3.0856776e16);
-}
diff --git a/src/uebung07/quantities/plain/PlainQuantitiesDemo.java b/src/uebung07/quantities/plain/PlainQuantitiesDemo.java
deleted file mode 100644
index bfa6924..0000000
--- a/src/uebung07/quantities/plain/PlainQuantitiesDemo.java
+++ /dev/null
@@ -1,60 +0,0 @@
-package uebung07.quantities.plain;
-
-import static uebung07.quantities.plain.LengthUnit.KILOMETER;
-import static uebung07.quantities.plain.LengthUnit.MILE;
-import static uebung07.quantities.plain.LengthUnit.MILLIMETER;
-import static uebung07.quantities.plain.LengthUnit.PARSEC;
-import static uebung07.quantities.plain.TimeUnit.HOUR;
-import static uebung07.quantities.plain.TimeUnit.MINUTE;
-import static uebung07.quantities.plain.TimeUnit.SECOND;
-import static uebung07.quantities.plain.VelocityUnit.KMH;
-import static uebung07.quantities.plain.VelocityUnit.METER_PER_SECOND;
-import static uebung07.quantities.plain.VelocityUnit.MPH;
-
-public class PlainQuantitiesDemo {
-    public static void main(String[] args) {
-        final Length l1 = new Length(1, KILOMETER);
-        final Length l2 = new Length(1200, MILLIMETER);
-        final Length l3 = new Length(1, MILE);
-
-        System.out.println(l1);
-        System.out.println(l2);
-        System.out.println(l1 + " + " + l2 + " = " + l1.plus(l2));
-        System.out.println(l1 + " + " + l2 + " (in mm) = " + l1.plus(l2).to(MILLIMETER));
-
-        System.out.println(l3 + " / " + l1 + " = " + l3.div(l1));
-
-        final Time t1 = new Time(100, SECOND);
-        final Time t2 = new Time(5, HOUR);
-
-        System.out.println(t1);
-        System.out.println(t2);
-        System.out.println(t1.plus(t2));
-        System.out.println(t1.plus(t2).to(MINUTE));
-
-        final Velocity v1 = new Velocity(12, KMH);
-        final Velocity v2 = new Velocity(100, METER_PER_SECOND);
-
-        System.out.println(v1);
-        System.out.println(v2);
-        System.out.println(v2.to(KMH));
-        System.out.println(v1.plus(v2));
-
-        final Length l4 = new Length(300, KILOMETER).to(PARSEC);
-        final Time t3 = new Time(2, HOUR);
-        final Velocity v3 = l4.div(t3);
-        System.out.println(l4 + " / " + l3 + " = " + v3);
-
-        System.out.println(v1 + " * " + t1 + " = " + v1.mult(t1).to(KILOMETER));
-
-        final Length l5 = v3.mult(t1.to(HOUR));
-        System.out.println(v3 + " * " + t1 + " = " + l5);
-
-        final Time t5 = l4.div(v2);
-        System.out.println(l4 + " / " + v2 + " = " + t5.to(MINUTE));
-
-        Velocity v5 = new Velocity(55, MPH);
-        System.out.println(v5 + " = " + v5.format("%4.1f %s", KMH));
-        System.out.println((v5.mult(new Time(30, MINUTE)).to(MILE)));
-    }
-}
diff --git a/src/uebung07/quantities/plain/Quantity.java b/src/uebung07/quantities/plain/Quantity.java
deleted file mode 100644
index b2d6e70..0000000
--- a/src/uebung07/quantities/plain/Quantity.java
+++ /dev/null
@@ -1,28 +0,0 @@
-package uebung07.quantities.plain;
-
-public abstract class Quantity {
-    public final double value;
-    public final Unit unit;
-
-    protected Quantity(double value, Unit unit) {
-        this.value = value;
-        this.unit = unit;
-    }
-
-    public double getBaseValue() {
-        return value * unit.baseFactor;
-    }
-
-    public double value(Unit unit) {
-        return getBaseValue() / unit.baseFactor;
-    }
-
-    @Override
-    public String toString() {
-        return value + " " + unit;
-    }
-
-    public String format(String fmt, Unit unit) {
-        return String.format(fmt, value(unit), unit);
-    }
-}
diff --git a/src/uebung07/quantities/plain/Time.java b/src/uebung07/quantities/plain/Time.java
deleted file mode 100644
index 99c2044..0000000
--- a/src/uebung07/quantities/plain/Time.java
+++ /dev/null
@@ -1,41 +0,0 @@
-package uebung07.quantities.plain;
-
-import static uebung07.quantities.plain.LengthUnit.METER;
-
-public class Time extends Quantity{
-    private final TimeUnit unit;
-
-    public Time(double value, TimeUnit unit) {
-        super(value, unit);
-        this.unit = unit;
-    }
-
-    public Time plus(Time other) {
-        return new Time( value + other.getBaseValue() / unit.baseFactor, unit);
-    }
-
-    public Time minus(Time other) {
-        return new Time( value - other.getBaseValue() / unit.baseFactor, unit);
-    }
-
-    public Time mult(double f) {
-        return new Time( value * f, unit);
-    }
-
-    public Time div(double f) {
-        return new Time( value / f, unit);
-    }
-
-    public Time to(TimeUnit unit) {
-        return new Time(getBaseValue() / unit.baseFactor, unit)
-    }
-
-    public double div(Time other) {
-        return getBaseValue() / other.getBaseValue();
-    }
-
-    public Length mult(Velocity v) {
-        return new Length(this.value(METER), METER);
-    }
-
-}
diff --git a/src/uebung07/quantities/plain/Unit.java b/src/uebung07/quantities/plain/Unit.java
deleted file mode 100644
index efaa8d7..0000000
--- a/src/uebung07/quantities/plain/Unit.java
+++ /dev/null
@@ -1,16 +0,0 @@
-package uebung07.quantities.plain;
-
-public abstract class Unit {
-    public final String name;
-    public final double baseFactor;
-
-    public Unit(String name, double baseFactor) {
-        this.name = name;
-        this.baseFactor = baseFactor;
-    }
-
-    @Override
-    public String toString() {
-        return name;
-    }
-}
diff --git a/src/uebung10/logo/BlackForest.java b/src/uebung10/logo/BlackForest.java
new file mode 100644
index 0000000..cefb8d9
--- /dev/null
+++ b/src/uebung10/logo/BlackForest.java
@@ -0,0 +1,11 @@
+package uebung10.logo;
+
+public class BlackForest implements DarkForest{
+
+    @Override
+    public void breadCrumb(double x, double y) {
+        // TODO Auto-generated method stub
+        throw new UnsupportedOperationException("Unimplemented method 'breadCrumb'");
+    }
+
+}
diff --git a/src/uebung10/logo/HanselGretelVisitor.java b/src/uebung10/logo/HanselGretelVisitor.java
index 8fe1f5c..70921f0 100644
--- a/src/uebung10/logo/HanselGretelVisitor.java
+++ b/src/uebung10/logo/HanselGretelVisitor.java
@@ -47,23 +47,21 @@ public class HanselGretelVisitor implements Visitor<Void> {
     }
 
     private void breadCrumb() {
-        // TODO Auto-generated method stub
-        throw new UnsupportedOperationException("Unimplemented method 'breadCrumb'");
+        forest.breadCrumb(turtle.getX(), turtle.getY());
     }
 
     private void layTrail(double d) {
-        forest.breadCrumb(turtle.getX(), turtle.getY());
+        // TODO Auto-generated method stub
+        throw new UnsupportedOperationException("Unimplemented method 'layTrail'");
     }
 
     private abstract class State {
         abstract void go(double dist);
-        void up() {}
-        void down() {}
+        abstract void up();
+        abstract void down();
         }
 
-    private final State shortUp = new ShortUpState();// muss nicht geschrieben werden
-    private final State down = new DownState();// muss nicht geschrieben werden
-    private final State longUp = new State(){
+    private final State longUpState = new State(){
 
         @Override
         void go(double d) {turtle.go(d);}
@@ -71,25 +69,52 @@ public class HanselGretelVisitor implements Visitor<Void> {
         @Override
         void down(){
             breadCrumb();
-            state = down;
+            state = downState;
         }
 
+        @Override
+        void up() {}
+
     };
 
-    private class DownState extends State{
+    private final State downState = new State(){
+
+        @Override
         void go(double d){
             layTrail(d);
         }
 
-        void up(){state = shortUp;}
-    }
+        @Override
+        void up(){state = shortUpState;}
 
-    //TODO
-    private class ShortUpState extends State {
-        void go(double d){}
-        void up(){}
-        void down(){}
-    }
+        @Override
+        void down() {}
+    };
+
+    private final State shortUpState = new  State() {
+
+        @Override
+        void go(double dist) {
+            turtle.go(dist);
+            gap = gap + dist;
+
+            if (gap < s) {
+
+            } else {
+                gap = 0;
+                state = longUpState;
+            }
+        }
+
+        @Override
+        void up() {}
+
+        @Override
+        void down() {
+            state = downState;
+        }
+
+    };
 
 
     private void go(double d) {