diff --git a/src/TensorFlowNET.Core/APIs/tf.control.cs b/src/TensorFlowNET.Core/APIs/tf.control.cs
index dcccb6fe..f0805c25 100644
--- a/src/TensorFlowNET.Core/APIs/tf.control.cs
+++ b/src/TensorFlowNET.Core/APIs/tf.control.cs
@@ -20,6 +20,13 @@ namespace Tensorflow
 {
     public partial class tensorflow
     {
+        public Tensor cond(Tensor pred,
+            Func<ITensorOrOperation> true_fn = null,
+            Func<ITensorOrOperation> false_fn = null,
+            bool strict = false,
+            string name = null)
+            => control_flow_ops.cond(pred, true_fn, false_fn, strict: strict, name: name);
+
         public Tensor while_loop(Func<Tensor, Tensor> cond, Func<Tensor, Tensor> body, Tensor[] loop_vars,
             TensorShape shape_invariants = null,
             int parallel_iterations = 10,
diff --git a/src/TensorFlowNET.Core/APIs/tf.state.cs b/src/TensorFlowNET.Core/APIs/tf.state.cs
new file mode 100644
index 00000000..c57d03c6
--- /dev/null
+++ b/src/TensorFlowNET.Core/APIs/tf.state.cs
@@ -0,0 +1,25 @@
+/*****************************************************************************
+   Copyright 2018 The TensorFlow.NET Authors. All Rights Reserved.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+******************************************************************************/
+
+namespace Tensorflow
+{
+    public partial class tensorflow
+    {
+        public Tensor assign_add<T>(RefVariable @ref, T value,
+            bool use_locking = false, string name = null)
+            => state_ops.assign_add(@ref, value, use_locking: use_locking, name: name);
+    }
+}
diff --git a/src/TensorFlowNET.Core/Variables/RefVariable.Operators.cs b/src/TensorFlowNET.Core/Variables/RefVariable.Operators.cs
index b4c77226..4ee9db76 100644
--- a/src/TensorFlowNET.Core/Variables/RefVariable.Operators.cs
+++ b/src/TensorFlowNET.Core/Variables/RefVariable.Operators.cs
@@ -29,6 +29,10 @@ namespace Tensorflow
         public static Tensor operator -(RefVariable x, double y) => op_helper("sub", x, y);
         public static Tensor operator -(RefVariable x, Tensor y) => op_helper("sub", x, y);
 
+        public static Tensor operator <(RefVariable x, Tensor y) => op_helper("Less", x, y);
+
+        public static Tensor operator >(RefVariable x, Tensor y) => op_helper("Greater", x, y);
+
         private static Tensor op_helper<T>(string default_name, RefVariable x, T y)
         {
             var tensor1 = x.value();
diff --git a/src/TensorFlowNET.Core/Variables/gen_state_ops.py.cs b/src/TensorFlowNET.Core/Variables/gen_state_ops.py.cs
index 5c8744b6..24cb11f5 100644
--- a/src/TensorFlowNET.Core/Variables/gen_state_ops.py.cs
+++ b/src/TensorFlowNET.Core/Variables/gen_state_ops.py.cs
@@ -126,7 +126,7 @@ namespace Tensorflow
         //      name: A name for the operation(optional).
         //  Returns:
         //    A mutable `Tensor`. Has the same type as `ref`.
-        public static Tensor assign_add(RefVariable @ref, Tensor value, bool use_locking = false, string name = null)
+        public static Tensor assign_add<T>(RefVariable @ref, T value, bool use_locking = false, string name = null)
         {
             var _op = _op_def_lib._apply_op_helper("AssignAdd", name: name, args: new { @ref, value, use_locking });
             return _op.outputs[0];
diff --git a/src/TensorFlowNET.Core/Variables/state_ops.cs b/src/TensorFlowNET.Core/Variables/state_ops.cs
index 8f478f2d..cd8d4f3f 100644
--- a/src/TensorFlowNET.Core/Variables/state_ops.cs
+++ b/src/TensorFlowNET.Core/Variables/state_ops.cs
@@ -94,10 +94,15 @@ namespace Tensorflow
         //  Returns:
         //    Same as "ref".  Returned as a convenience for operations that want
         //    to use the new value after the variable has been updated.
-        public static Tensor assign_add(RefVariable @ref,
-            Tensor value,
+        public static Tensor assign_add<T>(RefVariable @ref,
+            T value,
             bool use_locking = false,
-            string name = null) => gen_state_ops.assign_add(@ref, value, use_locking: use_locking, name: name);
+            string name = null)
+        {
+            if (@ref.dtype.is_ref_dtype())
+                return gen_state_ops.assign_add(@ref, value, use_locking: use_locking, name: name);
+            throw new NotImplementedException("assign_add");
+        }
 
         public static Tensor scatter_add(RefVariable @ref, Tensor indices, Tensor updates, bool use_locking = false, string name = null)
         {