diff --git a/Source/Engine/Gramambular/GramambularTest.cpp b/Source/Engine/Gramambular/GramambularTest.cpp
index 5868382a..d9ea65a3 100644
--- a/Source/Engine/Gramambular/GramambularTest.cpp
+++ b/Source/Engine/Gramambular/GramambularTest.cpp
@@ -22,7 +22,219 @@
 // OTHER DEALINGS IN THE SOFTWARE.
 
 #include "gtest/gtest.h"
+#include <algorithm>
+#include <iostream>
+#include <map>
+#include <vector>
+#include <cstdlib>
+#include <sstream>
+#include "Gramambular.h"
 
-TEST(GramambularTest, Trivial) {
-  ASSERT_EQ(1, 1);
+const char* SampleData = R"(
+#
+# The sample is from libtabe (http://sourceforge.net/projects/libtabe/)
+# last updated in 2002. The project was originally initiated by
+# Pai-Hsiang Hsiao in 1999.
+#
+# Libtabe is a frequency table of Taiwanese Mandarin words. The database
+# itself is, according to the tar file, released under the BSD License.
+#
+
+ㄙ 絲 -9.495858
+ㄙ 思 -9.006414
+ㄙ 私 -99.000000
+ㄙ 斯 -8.091803
+ㄙ 司 -99.000000
+ㄙ 嘶 -13.513987
+ㄙ 撕 -12.259095
+ㄍㄠ 高 -7.171551
+ㄎㄜ 顆 -10.574273
+ㄎㄜ 棵 -11.504072
+ㄎㄜ 刻 -10.450457
+ㄎㄜ 科 -7.171052
+ㄎㄜ 柯 -99.000000
+ㄍㄠ 膏 -11.928720
+ㄍㄠ 篙 -13.624335
+ㄍㄠ 糕 -12.390804
+ㄉㄜ˙ 的 -3.516024
+ㄉㄧˊ 的 -3.516024
+ㄉㄧˋ 的 -3.516024
+ㄓㄨㄥ 中 -5.809297
+ㄉㄜ˙ 得 -7.427179
+ㄍㄨㄥ 共 -8.381971
+ㄍㄨㄥ 供 -8.501463
+ㄐㄧˋ 既 -99.000000
+ㄐㄧㄣ 今 -8.034095
+ㄍㄨㄥ 紅 -8.858181
+ㄐㄧˋ 際 -7.608341
+ㄐㄧˋ 季 -99.000000
+ㄐㄧㄣ 金 -7.290109
+ㄐㄧˋ 騎 -10.939895
+ㄓㄨㄥ 終 -99.000000
+ㄐㄧˋ 記 -99.000000
+ㄐㄧˋ 寄 -99.000000
+ㄐㄧㄣ 斤 -99.000000
+ㄐㄧˋ 繼 -9.715317
+ㄐㄧˋ 計 -7.926683
+ㄐㄧˋ 暨 -8.373022
+ㄓㄨㄥ 鐘 -9.877580
+ㄐㄧㄣ 禁 -10.711079
+ㄍㄨㄥ 公 -7.877973
+ㄍㄨㄥ 工 -7.822167
+ㄍㄨㄥ 攻 -99.000000
+ㄍㄨㄥ 功 -99.000000
+ㄍㄨㄥ 宮 -99.000000
+ㄓㄨㄥ 鍾 -9.685671
+ㄐㄧˋ 繫 -10.425662
+ㄍㄨㄥ 弓 -99.000000
+ㄍㄨㄥ 恭 -99.000000
+ㄐㄧˋ 劑 -8.888722
+ㄐㄧˋ 祭 -10.204425
+ㄐㄧㄣ 浸 -11.378321
+ㄓㄨㄥ 盅 -99.000000
+ㄐㄧˋ 忌 -99.000000
+ㄐㄧˋ 技 -8.450826
+ㄐㄧㄣ 筋 -11.074890
+ㄍㄨㄥ 躬 -99.000000
+ㄐㄧˋ 冀 -12.045357
+ㄓㄨㄥ 忠 -99.000000
+ㄐㄧˋ 妓 -99.000000
+ㄐㄧˋ 濟 -9.517568
+ㄐㄧˋ 薊 -12.021587
+ㄐㄧㄣ 巾 -99.000000
+ㄐㄧㄣ 襟 -12.784206
+ㄋㄧㄢˊ 年 -6.086515
+ㄐㄧㄤˇ 講 -9.164384
+ㄐㄧㄤˇ 獎 -8.690941
+ㄐㄧㄤˇ 蔣 -10.127828
+ㄋㄧㄢˊ 黏 -11.336864
+ㄋㄧㄢˊ 粘 -11.285740
+ㄐㄧㄤˇ 槳 -12.492933
+ㄍㄨㄥㄙ 公司 -6.299461
+ㄎㄜㄐㄧˋ 科技 -6.736613
+ㄐㄧˋㄍㄨㄥ 濟公 -13.336653
+ㄐㄧㄤˇㄐㄧㄣ 獎金 -10.344678
+ㄋㄧㄢˊㄓㄨㄥ 年終 -11.668947
+ㄋㄧㄢˊㄓㄨㄥ 年中 -11.373044
+ㄍㄠㄎㄜㄐㄧˋ 高科技 -9.842421
+)";
+
+using namespace std;
+using namespace Formosa::Gramambular;
+
+class SimpleLM : public LanguageModel
+{
+ public:
+  SimpleLM(const char* input, bool swapKeyValue = false)
+  {
+    stringstream sstream(input);
+    while (sstream.good()) {
+      string line;
+      getline(sstream, line);
+
+      if (!line.size() || (line.size() && line[0] == '#')) {
+        continue;
+      }
+
+      stringstream linestream(line);
+      string col0;
+      string col1;
+      string col2;
+      linestream >> col0;
+      linestream >> col1;
+      linestream >> col2;
+
+      Unigram u;
+
+      if (swapKeyValue) {
+        u.keyValue.key = col1;
+        u.keyValue.value = col0;
+      }
+      else {
+        u.keyValue.key = col0;
+        u.keyValue.value = col1;
+      }
+
+      u.score = atof(col2.c_str());
+
+      m_db[u.keyValue.key].push_back(u);
+    }
+  }
+
+  const vector<Bigram> bigramsForKeys(const string &preceedingKey, const string& key) override
+  {
+    return vector<Bigram>();
+  }
+
+  const vector<Unigram> unigramsForKey(const string &key) override
+  {
+    map<string, vector<Unigram> >::const_iterator f = m_db.find(key);
+    return f == m_db.end() ? vector<Unigram>() : (*f).second;
+  }
+
+  bool hasUnigramsForKey(const string& key) override
+  {
+    map<string, vector<Unigram> >::const_iterator f = m_db.find(key);
+    return f != m_db.end();
+  }
+
+ protected:
+  map<string, vector<Unigram> > m_db;
+};
+
+TEST(GramambularTest, InputTest) {
+  SimpleLM lm(SampleData);
+
+  BlockReadingBuilder builder(&lm);
+  builder.insertReadingAtCursor("ㄍㄠ");
+  builder.insertReadingAtCursor("ㄐㄧˋ");
+  builder.setCursorIndex(1);
+  builder.insertReadingAtCursor("ㄎㄜ");
+  builder.setCursorIndex(0);
+  builder.deleteReadingAfterCursor();
+  builder.insertReadingAtCursor("ㄍㄠ");
+  builder.setCursorIndex(builder.length());
+  builder.insertReadingAtCursor("ㄍㄨㄥ");
+  builder.insertReadingAtCursor("ㄙ");
+  builder.insertReadingAtCursor("ㄉㄜ˙");
+  builder.insertReadingAtCursor("ㄋㄧㄢˊ");
+  builder.insertReadingAtCursor("ㄓㄨㄥ");
+  builder.insertReadingAtCursor("ㄐㄧㄤˇ");
+  builder.insertReadingAtCursor("ㄐㄧㄣ");
+
+  Walker walker(&builder.grid());
+
+  vector<NodeAnchor> walked = walker.reverseWalk(builder.grid().width(), 0.0);
+  reverse(walked.begin(), walked.end());
+
+  vector<string> composed;
+  for (vector<NodeAnchor>::iterator wi = walked.begin() ; wi != walked.end() ; ++wi) {
+    composed.push_back((*wi).node->currentKeyValue().value);
+  }
+  ASSERT_EQ(composed, (vector<string>{"高科技", "公司", "的", "年中", "獎金"}));
+}
+
+TEST(GramambularTest, WordSegmentationTest) {
+  SimpleLM lm2(SampleData, true);
+  BlockReadingBuilder builder2(&lm2);
+  builder2.insertReadingAtCursor("高");
+  builder2.insertReadingAtCursor("科");
+  builder2.insertReadingAtCursor("技");
+  builder2.insertReadingAtCursor("公");
+  builder2.insertReadingAtCursor("司");
+  builder2.insertReadingAtCursor("的");
+  builder2.insertReadingAtCursor("年");
+  builder2.insertReadingAtCursor("終");
+  builder2.insertReadingAtCursor("獎");
+  builder2.insertReadingAtCursor("金");
+  Walker walker2(&builder2.grid());
+
+  vector<NodeAnchor> walked = walker2.reverseWalk(builder2.grid().width(), 0.0);
+  reverse(walked.begin(), walked.end());
+
+  vector<string> segmented;
+  for (vector<NodeAnchor>::iterator wi = walked.begin(); wi != walked.end(); ++wi) {
+    segmented.push_back((*wi).node->currentKeyValue().key);
+  }
+  ASSERT_EQ(segmented, (vector<string>{"高科技", "公司", "的", "年終", "獎金"}));
 }