diff --git a/Cast.cs b/Cast.cs
index e8ad79b..58f28c5 100644
--- a/Cast.cs
+++ b/Cast.cs
@@ -33,7 +33,30 @@ namespace ln.types
                 !Explicit(value, value.GetType(), targetType, out casted)
                 )
 			{
-				casted = Convert.ChangeType(value, targetType);
+                if (targetType.IsEnum)
+                {
+                    if (value is string sValue)
+                    {
+                        casted = Enum.Parse(targetType, sValue);
+                    } else
+                    {
+                        throw new NotSupportedException();
+                    }
+                }
+                else if (targetType.IsArray)
+                {
+                    Array array = value as Array;
+                    Array castedArray = Array.CreateInstance(targetType.GetElementType(), array.Length);
+
+                    for (int n = 0; n < array.Length; n++)
+                        castedArray.SetValue(To(array.GetValue(n), targetType.GetElementType()), n);
+
+                    casted = castedArray;
+                }
+                else
+                {
+                    casted = Convert.ChangeType(value, targetType);
+                }
 			}
             return casted;
         }
diff --git a/ln.types.csproj b/ln.types.csproj
index 37fda00..7c6b08e 100644
--- a/ln.types.csproj
+++ b/ln.types.csproj
@@ -148,6 +148,7 @@
     <Compile Include="reflection\ObjectPool.cs" />
     <Compile Include="attributes\IdentityAttribute.cs" />
     <Compile Include="reflection\ObjectPoolValue.cs" />
+    <Compile Include="reflection\TypeExtensions.cs" />
   </ItemGroup>
   <ItemGroup>
     <Folder Include="odb\" />
diff --git a/reflection/AttributeDescriptor.cs b/reflection/AttributeDescriptor.cs
index ad5fd0b..1b3d283 100644
--- a/reflection/AttributeDescriptor.cs
+++ b/reflection/AttributeDescriptor.cs
@@ -27,11 +27,13 @@ namespace ln.types.reflection
         {
             Owner = propertyInfo.DeclaringType;
             IsPublic = propertyInfo.GetGetMethod().IsPublic;
-            IsReadonly = !(propertyInfo.CanWrite && propertyInfo.GetSetMethod().IsPublic);
+            IsReadonly = !(propertyInfo.CanWrite && propertyInfo.GetSetMethod(true).IsPublic);
             AttributeName = propertyInfo.Name;
             AttributeType = propertyInfo.PropertyType;
 
-            SetAction = propertyInfo.SetValue;
+            if (propertyInfo.CanWrite)
+                SetAction = propertyInfo.SetValue;
+
             GetFunc = propertyInfo.GetValue;
         }
         public AttributeDescriptor(FieldInfo fieldInfo)
@@ -42,13 +44,18 @@ namespace ln.types.reflection
             AttributeName = fieldInfo.Name;
             AttributeType = fieldInfo.FieldType;
 
-            SetAction = fieldInfo.SetValue;
+            if (!fieldInfo.IsInitOnly)
+                SetAction = fieldInfo.SetValue;
+
             GetFunc = fieldInfo.GetValue;
         }
 
         public TypeDescriptor TypeDescriptor => TypeDescriptor.GetDescriptor(Owner);
 
         public object GetValue(object instance) => GetFunc(instance);
-        public void SetValue(object instance, object value) => SetAction(instance, value);
+        public void SetValue(object instance, object value) {
+            if (SetAction != null)
+                SetAction(instance, value);
+        }
     }
 }
diff --git a/reflection/ObjectPool.cs b/reflection/ObjectPool.cs
index f2b8e8f..8a72467 100644
--- a/reflection/ObjectPool.cs
+++ b/reflection/ObjectPool.cs
@@ -1,6 +1,7 @@
 using System;
 using ln.types.btree;
 using System.Collections.Generic;
+using System.Linq;
 namespace ln.types.reflection
 {
     public class ObjectPool
@@ -24,10 +25,22 @@ namespace ln.types.reflection
             getIdentity = getIdentityDelegate;
         }
 
-        public IEnumerable<object> Identities => objects.Keys;
-        public IEnumerable<object> Instances => objects.Values;
+        public IEnumerable<object> Identities => objects.Keys.Concat(derivedTypes.SelectMany((op)=>op.Identities));
+        public IEnumerable<object> Instances => objects.Values.Concat(derivedTypes.SelectMany((op) => op.Instances));
+        public IEnumerable<object> OwnInstances => objects.Values;
 
-        public object this[object identity] => objects[identity];
+        public object this[object identity]
+        {
+            get
+            {
+                if (objects.ContainsKey(identity))
+                    return objects[identity];
+                foreach (ObjectPool derivedPool in derivedTypes)
+                    if (derivedPool.objects.ContainsKey(identity))
+                        return derivedPool.objects[identity];
+                throw new KeyNotFoundException();
+            }
+        }
 
         public void Add(object o) => objects.Add(GetIdentity(o), o);
         public void Remove(object identity) => objects.Remove(identity);
diff --git a/reflection/ObjectPoolContainer.cs b/reflection/ObjectPoolContainer.cs
index 5f88c0c..367f4c4 100644
--- a/reflection/ObjectPoolContainer.cs
+++ b/reflection/ObjectPoolContainer.cs
@@ -19,6 +19,8 @@ namespace ln.types.reflection
         public ObjectPool this[string typeName] => objectPools[typeName];
         public ObjectPool this[Type type] => objectPools[type.Name];
 
+        public bool KnowsType(Type type) => objectPools.ContainsKey(type.Name);
+
         public ObjectPoolContainer AddType(Type type) => AddType(type, null);
         public ObjectPoolContainer AddType(Type type,String identityAttribute)
         {
@@ -44,7 +46,17 @@ namespace ln.types.reflection
 
         public void SetupDerivedTypes(Type type)
         {
+            Type current = type.BaseType;
+            while (!object.Equals(current, typeof(object)))
+            {
+                if (objectPools.ContainsKey(current.Name))
+                {
+                    objectPools[current.Name].AddDerivedTypePool(objectPools[type.Name]);
+                    break;
+                }
 
+                current = current.BaseType;
+            }
         }
 
 
diff --git a/reflection/TypeDescriptor.cs b/reflection/TypeDescriptor.cs
index 6a146ca..2f1f91a 100644
--- a/reflection/TypeDescriptor.cs
+++ b/reflection/TypeDescriptor.cs
@@ -20,6 +20,8 @@ namespace ln.types.reflection
 
         public TypeDescriptor(Type type)
         {
+            Type = type;
+
             typeDescriptors[type] = this;
 
             foreach (FieldInfo fieldInfo in type.GetFields(BindingFlags.Instance | BindingFlags.Public))
@@ -31,13 +33,15 @@ namespace ln.types.reflection
         }
 
         public IEnumerable<string> AttributeNames => attributeDescriptors.Keys;
+        public IEnumerable<AttributeDescriptor> AttributeDescriptors => attributeDescriptors.Values;
         public AttributeDescriptor GetAttributeDescriptor(string attributeName) => attributeDescriptors[attributeName];
         public bool ContainsAttribute(string attributeName) => attributeDescriptors.ContainsKey(attributeName);
 
+
         static Dictionary<Type, TypeDescriptor> typeDescriptors = new Dictionary<Type, TypeDescriptor>();
         public static TypeDescriptor GetDescriptor(Type type)
         {
-            if (typeDescriptors.TryGetValue(type, out TypeDescriptor typeDescriptor))
+            if (!typeDescriptors.TryGetValue(type, out TypeDescriptor typeDescriptor))
                 return new TypeDescriptor(type);
             return typeDescriptor;
         }
diff --git a/reflection/TypeExtensions.cs b/reflection/TypeExtensions.cs
new file mode 100644
index 0000000..e94d6f9
--- /dev/null
+++ b/reflection/TypeExtensions.cs
@@ -0,0 +1,21 @@
+using System;
+using System.Linq;
+namespace ln.types.reflection
+{
+    public static class TypeExtensions
+    {
+
+        public static bool HasGenericInterface<T>(this Type type) => HasGenericInterface(type, typeof(T).GetGenericTypeDefinition());
+        public static bool HasGenericInterface(this Type type, Type genericInterfaceType)
+        {
+            return type.GetInterfaces().Any(x => x.IsGenericType && x.GetGenericTypeDefinition() == genericInterfaceType);
+        }
+
+        public static Type GetGenericInterface<T>(this Type type) => GetGenericInterface(type, typeof(T).GetGenericTypeDefinition());
+        public static Type GetGenericInterface(this Type type, Type genericInterfaceType)
+        {
+            return type.GetInterfaces().First(x => x.IsGenericType && x.GetGenericTypeDefinition() == genericInterfaceType);
+        }
+
+    }
+}
diff --git a/threads/SchedulingPool.cs b/threads/SchedulingPool.cs
index 0dcdc2d..13f3990 100644
--- a/threads/SchedulingPool.cs
+++ b/threads/SchedulingPool.cs
@@ -47,15 +47,22 @@ namespace ln.types.threads
             ThreadPool = new Pool(nThreads);
             ThreadPool.Start();
 
-            schedulerThread = new Thread(scheduler);
-            schedulerThread.Start();
+            lock (this)
+            {
+                schedulerThread = new Thread(scheduler);
+                schedulerThread.Start();
+
+                Monitor.Wait(this);
+            }
         }
 
         void scheduler()
         {
-            while (true)
+            lock (this)
             {
-                lock (this)
+                Monitor.PulseAll(this);
+
+                while (true)
                 {
                     double now = DateTime.Now.ToUnixTimeMilliseconds();
                     if (schedule.Empty)