diff --git a/pp.A4-HandOverHandLocking/src/main/java/pp/ThreadsafeSimplifiedList.java b/pp.A4-HandOverHandLocking/src/main/java/pp/ThreadsafeSimplifiedList.java
index a6e5f71..f9bb9dc 100644
--- a/pp.A4-HandOverHandLocking/src/main/java/pp/ThreadsafeSimplifiedList.java
+++ b/pp.A4-HandOverHandLocking/src/main/java/pp/ThreadsafeSimplifiedList.java
@@ -3,137 +3,121 @@ package pp;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
 
-import net.jcip.annotations.ThreadSafe;
+public class ThreadsafeSimplifiedList<T>
+        implements SimplifiedList<T> {
 
-@ThreadSafe
-public class ThreadsafeSimplifiedList<T> implements SimplifiedList<T> {
-	private Node<T> first;
-	private final Lock listLock = new ReentrantLock();
+    private Node<T> head;
+    private final Lock listLock = new ReentrantLock();
 
-	private class Node<U> {
-		private U element;
-		private Node<U> prev;
-		private Node<U> next;
-		private final Lock lock = new ReentrantLock();
+    private class Node<U> {
+        private U element;
+        private Node<U> next;
+        private final Lock nodeLock;
 
-		private Node(U element, Node<U> prev, Node<U> next) {
-			super();
-			this.element = element;
-			this.prev = prev;
-			this.next = next;
-		}
-	}
+        private Node(U element, Node<U> prev, Node<U> next) {
+            super();
+            this.element = element;
+            this.next = next;
+            this.nodeLock = new ReentrantLock();
+        }
+    }
 
-	public ThreadsafeSimplifiedList() {
-		super();
-		this.first = null;
-	}
+    /**
+     * Returns the element at the specified position in this list.
+     *
+     * @param index index of the element to return
+     * @return the element at the specified position in this list
+     */
+    @Override
+    public T get(int index) {
+        this.listLock.lock();
+        var ptr = this.head;
+        ptr.nodeLock.lock();
+        this.listLock.unlock();
+        for (var i = 0; i < index; i++) {
+            if (ptr.next != null) {
+                ptr.next.nodeLock.lock();
+                var savePtr = ptr;
+                ptr = ptr.next;
+                savePtr.nodeLock.unlock();
+            } else {
+                throw new IndexOutOfBoundsException(index + " out of bounds");            
+            }
+        }
+        
+        try {return delay(ptr.element);} 
+        finally { ptr.nodeLock.unlock();}
+    }
 
-	/**
-	 * Returns the element at the specified position in this list.
-	 *
-	 * @param index index of the element to return
-	 * @return the element at the specified position in this list
-	 */
-	@Override
-	public T get(int index) {
-		this.listLock.lock();
-		var ptr = this.first;
-		ptr.lock.lock();
-		this.listLock.unlock();
-		for (var j = 0; j < index; j++) {
-			if (ptr.next != null) {
-				ptr.next.lock.lock();
-				var savePtr = ptr;
-				ptr = ptr.next;
-				savePtr.lock.unlock();
-			} else {
-				throw new IndexOutOfBoundsException(index + " out of bounds");
-			}
-		}
-		try {
-			return delay(ptr.element);
-		} finally {
-			ptr.lock.unlock();
-		}
-	}
+    /**
+     * Appends the specified element to the end of this list. There are no
+     * limitations on what elements may be added to this list.
+     * 
+     * @param element element to be appended to this list
+     * @return true
+     * @see java.util.Collection#add(Object)
+     *
+     */
+    @Override
+    public boolean add(T element) {
+        this.listLock.lock();
+        if (this.head != null) {
+            var ptr = this.head;
+            ptr.nodeLock.lock();
+            this.listLock.unlock();
+            while (ptr.next != null) {
+                ptr.next.nodeLock.lock();
+                var savePtr = ptr;
+                ptr = ptr.next;
+                savePtr.nodeLock.unlock();
+            }
+            ptr.next = new Node<>(element, ptr, null);
+            ptr.nodeLock.unlock();
+        } else {
+            this.head = new Node<>(element, null, null);
+            this.listLock.unlock();
+        }
+        return true;
+    }
 
-	/**
-	 * Appends the specified element to the end of this list. There are no
-	 * limitations on what elements may be added to this list.
-	 * 
-	 * @param element element to be appended to this list
-	 * @return true
-	 * @see java.util.Collection#add(Object)
-	 *
-	 */
-	@Override
-	public boolean add(T element) {
-		this.listLock.lock();
-		if (this.first != null) {
-			var ptr = this.first;
-			ptr.lock.lock();
-			this.listLock.unlock();
-			while (ptr.next != null) {
-				ptr.next.lock.lock();
-				var saveNode = ptr;
-				ptr = ptr.next;
-				saveNode.lock.unlock();
-			}
-			ptr.next = new Node<>(element, ptr, null);
-		} else {
-			this.first = new Node<>(element, null, null);
-			this.listLock.unlock();
-		}
-		return true;
-	}
+    /**
+     * Replaces the element at the specified position in this list with the
+     * specified element.
+     * 
+     * @param index   index of the element to replace
+     * @param element element to be stored at the specified position
+     * @return the element previously at the specified position
+     */
+    @Override
+    public T set(int index, T element) {
+        this.listLock.lock();
+        var ptr = this.head;
+        ptr.nodeLock.lock();
+        this.listLock.unlock();
+        for (var i = 0; i < index; i++) {
+            if (ptr.next != null) {
+                ptr.next.nodeLock.lock();
+                var savePtr = ptr;
+                ptr = ptr.next;
+                savePtr.nodeLock.unlock();
+            } else 
+                throw new IndexOutOfBoundsException(index + " out of bounds");           
+           
+        }
+        ptr.element = element;
+        ptr.nodeLock.unlock();
+        return element;
+    }
 
-	/**
-	 * Replaces the element at the specified position in this list with the
-	 * specified element.
-	 * 
-	 * @param index   index of the element to replace
-	 * @param element element to be stored at the specified position
-	 * @return the element previously at the specified position
-	 */
-	@Override
-	public T set(int index, T element) {
-		this.listLock.lock();
-		var ptr = this.first;
-		ptr.lock.lock();
-		this.listLock.unlock();
-		for (var j = 0; j < index; j++) {
-			if (ptr.next != null) {
-				ptr.next.lock.lock();
-				var saveNode = ptr;
-				ptr = ptr.next;
-				saveNode.lock.unlock();
-			} else {
-				throw new IndexOutOfBoundsException(index + " out of bounds");
-			}
-		}
-		try {
-			var prevElement = ptr.element;
-			ptr.element = element;
-			return prevElement;
-		} finally {
-			ptr.lock.unlock();
-		}
-	}
-
-	/**
-	 * Returns true if this list contains no elements.
-	 * 
-	 * @return true if this list contains no elements
-	 */
-	@Override
-	public boolean isEmpty() {
-		this.listLock.lock();
-		try {
-			return this.first == null;
-		} finally {
-			this.listLock.unlock();
-		}
-	}
+    /**
+     * Returns true if this list contains no elements.
+     * 
+     * @return true if this list contains no elements
+     */
+    @Override
+    public boolean isEmpty() {
+        this.listLock.lock();
+        try { return this.head == null; } 
+        finally { this.listLock.unlock();}
+    }
 }
-