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diff --git a/runtimes/neurun/src/graph/verifier/IVerifier.cc b/runtimes/neurun/src/graph/verifier/IVerifier.cc
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+++ b/runtimes/neurun/src/graph/verifier/IVerifier.cc
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+/*
+ * Copyright (c) 2018 Samsung Electronics Co., Ltd. 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.
+ */
+
+#include "IVerifier.h"
+
+#include "graph/Graph.h"
+
+namespace neurun
+{
+namespace graph
+{
+namespace verifier
+{
+
+bool DAGChecker::verify(const Graph &graph) const
+{
+  auto &operations = graph.operations();
+  bool cyclic = false;
+  std::vector<bool> visited(operations.size(), false);
+  std::vector<bool> on_stack(operations.size(), false);
+
+  std::function<void(const operation::Index &index, const operation::Node &)> dfs_recursive =
+      [&](const operation::Index &index, const operation::Node &node) -> void {
+    if (on_stack[index.value()])
+      cyclic = true;
+    if (visited[index.value()])
+      return;
+    visited[index.value()] = true;
+    on_stack[index.value()] = true;
+
+    auto outputs = node.getOutputs();
+    for (auto output : outputs)
+    {
+      // TODO Fix traversing algorithm
+      //      Every time need to search for operations that has `outgoing` as incoming from all
+      //      operations but we can hold that info cached
+      operations.iterate([&](const operation::Index &cand_index, const operation::Node &cand_node) {
+        auto inputs = cand_node.getInputs();
+        for (auto input : inputs)
+        {
+          if (output == input)
+          {
+            dfs_recursive(cand_index, cand_node);
+          }
+        }
+      });
+    }
+
+    on_stack[index.value()] = false;
+  };
+
+  operations.iterate(dfs_recursive);
+
+  return !cyclic;
+}
+
+} // namespace verifier
+} // namespace graph
+} // namespace neurun