diff --git a/include/fdeep/convolution.hpp b/include/fdeep/convolution.hpp
index eba8a166..befd8f2e 100644
--- a/include/fdeep/convolution.hpp
+++ b/include/fdeep/convolution.hpp
@@ -59,12 +59,6 @@ namespace internal {
         return { shape, filters.size(), biases, use_bias, filter_mats };
     }
 
-    inline convolution_filter_matrices generate_im2col_single_filter_matrix(
-        const filter& filter)
-    {
-        return generate_im2col_filter_matrix(filter_vec(1, filter));
-    }
-
     inline tensor init_conv_output_tensor(
         std::size_t out_height,
         std::size_t out_width,
diff --git a/include/fdeep/import_model.hpp b/include/fdeep/import_model.hpp
index e09931ab..0293a3d4 100644
--- a/include/fdeep/import_model.hpp
+++ b/include/fdeep/import_model.hpp
@@ -130,35 +130,36 @@ namespace internal {
         return fplus::just(result);
     }
 
-    inline tensor_shape_variable create_tensor_shape_variable(const nlohmann::json& data)
+    inline tensor_shape_variable create_tensor_shape_variable_offset(
+        const nlohmann::json& data, std::size_t offset)
     {
         assertion(data.is_array(), "tensor_shape_variable needs to be an array");
         assertion(data.size() > 0, "need at least one dimension");
-        if (data.size() == 1)
+        if (data.size() == 1 + offset)
             return tensor_shape_variable(
-                create_maybe_size_t(data[0]));
-        if (data.size() == 2)
+                create_maybe_size_t(data[0 + offset]));
+        if (data.size() == 2 + offset)
             return tensor_shape_variable(
-                create_maybe_size_t(data[0]),
-                create_maybe_size_t(data[1]));
-        if (data.size() == 3)
+                create_maybe_size_t(data[0 + offset]),
+                create_maybe_size_t(data[1 + offset]));
+        if (data.size() == 3 + offset)
             return tensor_shape_variable(
-                create_maybe_size_t(data[0]),
-                create_maybe_size_t(data[1]),
-                create_maybe_size_t(data[2]));
-        if (data.size() == 4)
+                create_maybe_size_t(data[0 + offset]),
+                create_maybe_size_t(data[1 + offset]),
+                create_maybe_size_t(data[2 + offset]));
+        if (data.size() == 4 + offset)
             return tensor_shape_variable(
-                create_maybe_size_t(data[0]),
-                create_maybe_size_t(data[1]),
-                create_maybe_size_t(data[2]),
-                create_maybe_size_t(data[3]));
-        if (data.size() == 5)
+                create_maybe_size_t(data[0 + offset]),
+                create_maybe_size_t(data[1 + offset]),
+                create_maybe_size_t(data[2 + offset]),
+                create_maybe_size_t(data[3 + offset]));
+        if (data.size() == 5 + offset)
             return tensor_shape_variable(
-                create_maybe_size_t(data[0]),
-                create_maybe_size_t(data[1]),
-                create_maybe_size_t(data[2]),
-                create_maybe_size_t(data[3]),
-                create_maybe_size_t(data[4]));
+                create_maybe_size_t(data[0 + offset]),
+                create_maybe_size_t(data[1 + offset]),
+                create_maybe_size_t(data[2 + offset]),
+                create_maybe_size_t(data[3 + offset]),
+                create_maybe_size_t(data[4 + offset]));
 
         raise_error("tensor_shape_variable needs 1, 2, 3, 4 or 5 dimensions");
         return tensor_shape_variable(
@@ -169,43 +170,14 @@ namespace internal {
             fplus::nothing<std::size_t>()); // Is never called
     }
 
-    inline tensor_shape_variable create_tensor_shape_variable_leading_null(const nlohmann::json& data)
+    inline tensor_shape_variable create_tensor_shape_variable(const nlohmann::json& data)
     {
-        assertion(data.is_array(), "tensor_shape_variable needs to be an array");
-        assertion(data.size() > 0, "need at least one dimension");
-        if (data.size() == 2)
-            return tensor_shape_variable(
-                create_maybe_size_t(data[1]));
-        if (data.size() == 3)
-            return tensor_shape_variable(
-                create_maybe_size_t(data[1]),
-                create_maybe_size_t(data[2]));
-        if (data.size() == 4)
-            return tensor_shape_variable(
-                create_maybe_size_t(data[1]),
-                create_maybe_size_t(data[2]),
-                create_maybe_size_t(data[3]));
-        if (data.size() == 5)
-            return tensor_shape_variable(
-                create_maybe_size_t(data[1]),
-                create_maybe_size_t(data[2]),
-                create_maybe_size_t(data[3]),
-                create_maybe_size_t(data[4]));
-        if (data.size() == 6)
-            return tensor_shape_variable(
-                create_maybe_size_t(data[1]),
-                create_maybe_size_t(data[2]),
-                create_maybe_size_t(data[3]),
-                create_maybe_size_t(data[4]),
-                create_maybe_size_t(data[5]));
+        return create_tensor_shape_variable_offset(data, 0);
+    }
 
-        raise_error("tensor_shape_variable needs 1, 2, 3, 4 or 5 dimensions");
-        return tensor_shape_variable(
-            fplus::nothing<std::size_t>(),
-            fplus::nothing<std::size_t>(),
-            fplus::nothing<std::size_t>(),
-            fplus::nothing<std::size_t>(),
-            fplus::nothing<std::size_t>()); // Is never called
+    inline tensor_shape_variable create_tensor_shape_variable_leading_null(const nlohmann::json& data)
+    {
+        return create_tensor_shape_variable_offset(data, 1);
     }
 
     inline tensor_shape create_tensor_shape(const nlohmann::json& data)
@@ -390,11 +362,6 @@ namespace internal {
         return std::make_shared<model_layer>(name, layers, inputs, outputs);
     }
 
-    inline void fill_with_zeros(float_vec& xs)
-    {
-        std::fill(std::begin(xs), std::end(xs), static_cast<float_type>(0));
-    }
-
     inline padding create_padding(const std::string& padding_str)
     {
         return fplus::throw_on_nothing(error("no padding"),
@@ -1067,15 +1034,6 @@ namespace internal {
         return data;
     }
 
-    inline std::string json_object_get_activation_with_default(const nlohmann::json& config,
-        const std::string& default_activation)
-    {
-        if (json_obj_has_member(config, "activation")) {
-            return get_activation_type(config["activation"]);
-        }
-        return default_activation;
-    }
-
     inline activation_layer_ptr create_activation_layer_type_name(
         const get_param_f& get_param,
         const nlohmann::json& data,
diff --git a/include/fdeep/recurrent_ops.hpp b/include/fdeep/recurrent_ops.hpp
index 33dc12e7..1f8945b4 100644
--- a/include/fdeep/recurrent_ops.hpp
+++ b/include/fdeep/recurrent_ops.hpp
@@ -17,11 +17,6 @@ namespace internal {
     template <int Count>
     using RowVector = Eigen::Matrix<float_type, 1, Count>;
 
-    inline float_type linear_activation(float_type x)
-    {
-        return x;
-    }
-
     inline float_type tanh_activation(float_type x)
     {
         return std::tanh(x);
@@ -49,11 +44,6 @@ namespace internal {
         return (x / static_cast<float_type>(6)) + static_cast<float_type>(0.5);
     }
 
-    inline float_type relu_activation(float_type x)
-    {
-        return std::max<float_type>(x, 0);
-    }
-
     inline float_type selu_activation(float_type x)
     {
         const float_type alpha = static_cast<float_type>(1.6732632423543772848170429916717);
diff --git a/include/fdeep/tensor.hpp b/include/fdeep/tensor.hpp
index 4f4c63a1..3bfb89ee 100644
--- a/include/fdeep/tensor.hpp
+++ b/include/fdeep/tensor.hpp
@@ -187,16 +187,6 @@ namespace internal {
         return t.get(tensor_pos(static_cast<std::size_t>(0)));
     }
 
-    inline tensor from_singleton_value(float_type value)
-    {
-        return tensor(tensor_shape(static_cast<std::size_t>(1)), value);
-    }
-
-    inline tensor tensor_with_changed_rank(const tensor& t, std::size_t rank)
-    {
-        return tensor(tensor_shape_with_changed_rank(t.shape(), rank), t.as_vector());
-    }
-
     template <typename F>
     tensor transform_tensor(F f, const tensor& m)
     {
@@ -900,17 +890,6 @@ namespace internal {
         return tensor(ts.front().shape(), std::move(result_values));
     }
 
-    // When using this function, make sure the data pointer is not invalidated
-    // before the last access to the returned matrix happens.
-    inline MappedRowMajorMatrixXf eigen_row_major_mat_from_shared_values(std::size_t height,
-        std::size_t width, float_type* data)
-    {
-        return MappedRowMajorMatrixXf(
-            data,
-            static_cast<EigenIndex>(height),
-            static_cast<EigenIndex>(width));
-    }
-
     inline RowMajorMatrixXf eigen_row_major_mat_from_values(std::size_t height,
         std::size_t width, const float_vec& values)
     {
@@ -920,14 +899,6 @@ namespace internal {
         return m;
     }
 
-    inline shared_float_vec eigen_row_major_mat_to_values(const RowMajorMatrixXf& m)
-    {
-        shared_float_vec result = fplus::make_shared_ref<float_vec>();
-        result->resize(static_cast<std::size_t>(m.rows() * m.cols()));
-        std::memcpy(result->data(), m.data(), result->size() * sizeof(float_type));
-        return result;
-    }
-
     inline tensor resize2d_nearest(const tensor& in_vol, const shape2& target_size)
     {
         tensor out_vol(tensor_shape(target_size.height_, target_size.width_, in_vol.shape().depth_), 0);