diff --git a/egs/slu/README.md b/egs/slu/README.md
new file mode 100755
index 000000000..38b491fc6
--- /dev/null
+++ b/egs/slu/README.md
@@ -0,0 +1,14 @@
+## Yesno recipe
+
+This is the simplest ASR recipe in `icefall`.
+
+It can be run on CPU and takes less than 30 seconds to
+get the following WER:
+
+```
+[test_set] %WER 0.42% [1 / 240, 0 ins, 1 del, 0 sub ]
+```
+
+Please refer to
+<https://icefall.readthedocs.io/en/latest/recipes/Non-streaming-ASR/yesno/index.html>
+for detailed instructions.
diff --git a/egs/slu/local/compile_hlg.py b/egs/slu/local/compile_hlg.py
new file mode 100755
index 000000000..a7df8f966
--- /dev/null
+++ b/egs/slu/local/compile_hlg.py
@@ -0,0 +1,136 @@
+#!/usr/bin/env python3
+
+"""
+This script takes as input lang_dir and generates HLG from
+
+    - H, the ctc topology, built from tokens contained in lang_dir/lexicon.txt
+    - L, the lexicon, built from lang_dir/L_disambig.pt
+
+        Caution: We use a lexicon that contains disambiguation symbols
+
+    - G, the LM, built from data/lm/G.fst.txt
+
+The generated HLG is saved in $lang_dir/HLG.pt
+"""
+import argparse
+import logging
+from pathlib import Path
+
+import k2
+import torch
+
+from icefall.lexicon import Lexicon
+
+
+def get_args():
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        "--lang-dir",
+        type=str,
+        help="""Input and output directory.
+        """,
+    )
+
+    return parser.parse_args()
+
+
+def compile_HLG(lang_dir: str) -> k2.Fsa:
+    """
+    Args:
+      lang_dir:
+        The language directory, e.g., data/lang_phone or data/lang_bpe_5000.
+
+    Return:
+      An FSA representing HLG.
+    """
+    lexicon = Lexicon(lang_dir)
+    max_token_id = max(lexicon.tokens)
+    logging.info(f"Building ctc_topo. max_token_id: {max_token_id}")
+    H = k2.ctc_topo(max_token_id)
+    L = k2.Fsa.from_dict(torch.load(f"{lang_dir}/L_disambig.pt"))
+
+    logging.info("Loading G.fst.txt")
+    with open(lang_dir / "G.fst.txt") as f:
+        G = k2.Fsa.from_openfst(f.read(), acceptor=False)
+
+    first_token_disambig_id = lexicon.token_table["#0"]
+    first_word_disambig_id = lexicon.word_table["#0"]
+
+    L = k2.arc_sort(L)
+    G = k2.arc_sort(G)
+
+    logging.info("Intersecting L and G")
+    LG = k2.compose(L, G)
+    logging.info(f"LG shape: {LG.shape}")
+
+    logging.info("Connecting LG")
+    LG = k2.connect(LG)
+    logging.info(f"LG shape after k2.connect: {LG.shape}")
+
+    logging.info(type(LG.aux_labels))
+    logging.info("Determinizing LG")
+
+    LG = k2.determinize(LG)
+    logging.info(type(LG.aux_labels))
+
+    logging.info("Connecting LG after k2.determinize")
+    LG = k2.connect(LG)
+
+    logging.info("Removing disambiguation symbols on LG")
+
+    # LG.labels[LG.labels >= first_token_disambig_id] = 0
+    # see https://github.com/k2-fsa/k2/pull/1140
+    labels = LG.labels
+    labels[labels >= first_token_disambig_id] = 0
+    LG.labels = labels
+
+    assert isinstance(LG.aux_labels, k2.RaggedTensor)
+    LG.aux_labels.values[LG.aux_labels.values >= first_word_disambig_id] = 0
+
+    LG = k2.remove_epsilon(LG)
+    logging.info(f"LG shape after k2.remove_epsilon: {LG.shape}")
+
+    LG = k2.connect(LG)
+    LG.aux_labels = LG.aux_labels.remove_values_eq(0)
+
+    logging.info("Arc sorting LG")
+    LG = k2.arc_sort(LG)
+
+    logging.info("Composing H and LG")
+    # CAUTION: The name of the inner_labels is fixed
+    # to `tokens`. If you want to change it, please
+    # also change other places in icefall that are using
+    # it.
+    HLG = k2.compose(H, LG, inner_labels="tokens")
+
+    logging.info("Connecting LG")
+    HLG = k2.connect(HLG)
+
+    logging.info("Arc sorting LG")
+    HLG = k2.arc_sort(HLG)
+    logging.info(f"HLG.shape: {HLG.shape}")
+
+    return HLG
+
+
+def main():
+    args = get_args()
+    lang_dir = Path(args.lang_dir)
+
+    if (lang_dir / "HLG.pt").is_file():
+        logging.info(f"{lang_dir}/HLG.pt already exists - skipping")
+        return
+
+    logging.info(f"Processing {lang_dir}")
+
+    HLG = compile_HLG(lang_dir)
+    logging.info(f"Saving HLG.pt to {lang_dir}")
+    torch.save(HLG.as_dict(), f"{lang_dir}/HLG.pt")
+
+
+if __name__ == "__main__":
+    formatter = "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
+
+    logging.basicConfig(format=formatter, level=logging.INFO)
+
+    main()
diff --git a/egs/slu/local/compute_fbank_slu.py b/egs/slu/local/compute_fbank_slu.py
new file mode 100755
index 000000000..e4ddfd73f
--- /dev/null
+++ b/egs/slu/local/compute_fbank_slu.py
@@ -0,0 +1,91 @@
+#!/usr/bin/env python3
+
+"""
+This file computes fbank features of the Fluent Speech Commands dataset.
+It looks for manifests in the directory data/manifests.
+
+The generated fbank features are saved in data/fbank.
+"""
+
+import logging
+import os
+from pathlib import Path
+
+import torch
+from lhotse import CutSet, Fbank, FbankConfig, LilcomChunkyWriter
+from lhotse.recipes.utils import read_manifests_if_cached
+
+from icefall.utils import get_executor
+
+# Torch's multithreaded behavior needs to be disabled or it wastes a
+# lot of CPU and slow things down.
+# Do this outside of main() in case it needs to take effect
+# even when we are not invoking the main (e.g. when spawning subprocesses).
+torch.set_num_threads(1)
+torch.set_num_interop_threads(1)
+
+
+def compute_fbank_slu():
+    src_dir = Path("data/manifests")
+    output_dir = Path("data/fbank")
+
+    # This dataset is rather small, so we use only one job
+    num_jobs = min(1, os.cpu_count())
+    num_mel_bins = 23
+
+    dataset_parts = (
+        "train",
+        "valid",
+        "test",
+    )
+    prefix = "slu"
+    suffix = "jsonl.gz"
+    manifests = read_manifests_if_cached(
+        dataset_parts=dataset_parts,
+        output_dir=src_dir,
+        prefix=prefix,
+        suffix=suffix,
+    )
+    assert manifests is not None
+
+    assert len(manifests) == len(dataset_parts), (
+        len(manifests),
+        len(dataset_parts),
+        list(manifests.keys()),
+        dataset_parts,
+    )
+
+    extractor = Fbank(FbankConfig(sampling_rate=16000, num_mel_bins=num_mel_bins))
+
+    with get_executor() as ex:  # Initialize the executor only once.
+        for partition, m in manifests.items():
+            cuts_file = output_dir / f"{prefix}_cuts_{partition}.{suffix}"
+            if cuts_file.is_file():
+                logging.info(f"{partition} already exists - skipping.")
+                continue
+            logging.info(f"Processing {partition}")
+            cut_set = CutSet.from_manifests(
+                recordings=m["recordings"],
+                supervisions=m["supervisions"],
+            )
+            if "train" in partition:
+                cut_set = (
+                    cut_set + cut_set.perturb_speed(0.9) + cut_set.perturb_speed(1.1)
+                )
+            cut_set = cut_set.compute_and_store_features(
+                extractor=extractor,
+                storage_path=f"{output_dir}/{prefix}_feats_{partition}",
+                # when an executor is specified, make more partitions
+                num_jobs=num_jobs if ex is None else 1,  # use one job
+                executor=ex,
+                storage_type=LilcomChunkyWriter,
+            )
+            cut_set.to_file(cuts_file)
+
+
+if __name__ == "__main__":
+    formatter = "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
+
+    logging.basicConfig(format=formatter, level=logging.INFO)
+
+    compute_fbank_slu()
diff --git a/egs/slu/local/generate_lexicon.py b/egs/slu/local/generate_lexicon.py
new file mode 100755
index 000000000..6613e4217
--- /dev/null
+++ b/egs/slu/local/generate_lexicon.py
@@ -0,0 +1,47 @@
+import pandas, argparse
+from tqdm import tqdm
+
+def generate_lexicon(corpus_dir, lm_dir):
+    data = pandas.read_csv(str(corpus_dir) + '/data/train_data.csv', index_col = 0, header = 0)
+    vocab_transcript = set()
+    vocab_frames = set()
+    transcripts = data['transcription'].tolist()
+    frames = list(i for i in zip(data['action'].tolist(), data['object'].tolist(), data['location'].tolist()))
+
+    for transcript in tqdm(transcripts):
+        for word in transcript.split():
+            vocab_transcript.add(word)
+
+    for frame in tqdm(frames):
+        for word in frame:
+            vocab_frames.add('_'.join(word.split()))
+    
+    with open(lm_dir + '/words_transcript.txt', 'w') as lexicon_transcript_file:
+        lexicon_transcript_file.write("<UNK> 1" + '\n')
+        lexicon_transcript_file.write("<s> 2" + '\n')
+        lexicon_transcript_file.write("</s> 0" + '\n')
+        id = 3
+        for vocab in vocab_transcript:
+            lexicon_transcript_file.write(vocab + ' ' + str(id) + '\n')
+            id += 1
+
+    with open(lm_dir + '/words_frames.txt', 'w') as lexicon_frames_file:
+        lexicon_frames_file.write("<UNK> 1" + '\n')
+        lexicon_frames_file.write("<s> 2" + '\n')
+        lexicon_frames_file.write("</s> 0" + '\n')
+        id = 3
+        for vocab in vocab_frames:
+            lexicon_frames_file.write(vocab + ' ' + str(id) + '\n')
+            id += 1
+
+    
+parser = argparse.ArgumentParser()
+parser.add_argument('corpus_dir')
+parser.add_argument('lm_dir')
+
+def main():
+    args = parser.parse_args()
+    
+    generate_lexicon(args.corpus_dir, args.lm_dir)
+
+main()
\ No newline at end of file
diff --git a/egs/slu/local/prepare_lang.py b/egs/slu/local/prepare_lang.py
new file mode 100755
index 000000000..f4b6f6262
--- /dev/null
+++ b/egs/slu/local/prepare_lang.py
@@ -0,0 +1,364 @@
+#!/usr/bin/env python3
+
+# Copyright (c)  2021  Xiaomi Corporation (authors: Fangjun Kuang)
+
+"""
+This script takes as input a lexicon file "data/lang_phone/lexicon.txt"
+consisting of words and tokens (i.e., phones) and does the following:
+
+1. Add disambiguation symbols to the lexicon and generate lexicon_disambig.txt
+
+2. Generate tokens.txt, the token table mapping a token to a unique integer.
+
+3. Generate words.txt, the word table mapping a word to a unique integer.
+
+4. Generate L.pt, in k2 format. It can be loaded by
+
+        d = torch.load("L.pt")
+        lexicon = k2.Fsa.from_dict(d)
+
+5. Generate L_disambig.pt, in k2 format.
+"""
+import math
+from collections import defaultdict
+from pathlib import Path
+from typing import Any, Dict, List, Tuple
+
+import k2
+import torch
+
+from icefall.lexicon import read_lexicon, write_lexicon
+
+Lexicon = List[Tuple[str, List[str]]]
+
+
+def write_mapping(filename: str, sym2id: Dict[str, int]) -> None:
+    """Write a symbol to ID mapping to a file.
+
+    Note:
+      No need to implement `read_mapping` as it can be done
+      through :func:`k2.SymbolTable.from_file`.
+
+    Args:
+      filename:
+        Filename to save the mapping.
+      sym2id:
+        A dict mapping symbols to IDs.
+    Returns:
+      Return None.
+    """
+    with open(filename, "w", encoding="utf-8") as f:
+        for sym, i in sym2id.items():
+            f.write(f"{sym} {i}\n")
+
+
+def get_tokens(lexicon: Lexicon) -> List[str]:
+    """Get tokens from a lexicon.
+
+    Args:
+      lexicon:
+        It is the return value of :func:`read_lexicon`.
+    Returns:
+      Return a list of unique tokens.
+    """
+    ans = set()
+    for _, tokens in lexicon:
+        ans.update(tokens)
+    sorted_ans = sorted(list(ans))
+    return sorted_ans
+
+
+def get_words(lexicon: Lexicon) -> List[str]:
+    """Get words from a lexicon.
+
+    Args:
+      lexicon:
+        It is the return value of :func:`read_lexicon`.
+    Returns:
+      Return a list of unique words.
+    """
+    ans = set()
+    for word, _ in lexicon:
+        ans.add(word)
+    sorted_ans = sorted(list(ans))
+    return sorted_ans
+
+
+def add_disambig_symbols(lexicon: Lexicon) -> Tuple[Lexicon, int]:
+    """It adds pseudo-token disambiguation symbols #1, #2 and so on
+    at the ends of tokens to ensure that all pronunciations are different,
+    and that none is a prefix of another.
+
+    See also add_lex_disambig.pl from kaldi.
+
+    Args:
+      lexicon:
+        It is returned by :func:`read_lexicon`.
+    Returns:
+      Return a tuple with two elements:
+
+        - The output lexicon with disambiguation symbols
+        - The ID of the max disambiguation symbol that appears
+          in the lexicon
+    """
+
+    # (1) Work out the count of each token-sequence in the
+    # lexicon.
+    count = defaultdict(int)
+    for _, tokens in lexicon:
+        count[" ".join(tokens)] += 1
+
+    # (2) For each left sub-sequence of each token-sequence, note down
+    # that it exists (for identifying prefixes of longer strings).
+    issubseq = defaultdict(int)
+    for _, tokens in lexicon:
+        tokens = tokens.copy()
+        tokens.pop()
+        while tokens:
+            issubseq[" ".join(tokens)] = 1
+            tokens.pop()
+
+    # (3) For each entry in the lexicon:
+    # if the token sequence is unique and is not a
+    # prefix of another word, no disambig symbol.
+    # Else output #1, or #2, #3, ... if the same token-seq
+    # has already been assigned a disambig symbol.
+    ans = []
+
+    # We start with #1 since #0 has its own purpose
+    first_allowed_disambig = 1
+    max_disambig = first_allowed_disambig - 1
+    last_used_disambig_symbol_of = defaultdict(int)
+
+    for word, tokens in lexicon:
+        tokenseq = " ".join(tokens)
+        assert tokenseq != ""
+        if issubseq[tokenseq] == 0 and count[tokenseq] == 1:
+            ans.append((word, tokens))
+            continue
+
+        cur_disambig = last_used_disambig_symbol_of[tokenseq]
+        if cur_disambig == 0:
+            cur_disambig = first_allowed_disambig
+        else:
+            cur_disambig += 1
+
+        if cur_disambig > max_disambig:
+            max_disambig = cur_disambig
+        last_used_disambig_symbol_of[tokenseq] = cur_disambig
+        tokenseq += f" #{cur_disambig}"
+        ans.append((word, tokenseq.split()))
+    return ans, max_disambig
+
+
+def generate_id_map(symbols: List[str]) -> Dict[str, int]:
+    """Generate ID maps, i.e., map a symbol to a unique ID.
+
+    Args:
+      symbols:
+        A list of unique symbols.
+    Returns:
+      A dict containing the mapping between symbols and IDs.
+    """
+    return {sym: i for i, sym in enumerate(symbols)}
+
+
+def add_self_loops(
+    arcs: List[List[Any]], disambig_token: int, disambig_word: int
+) -> List[List[Any]]:
+    """Adds self-loops to states of an FST to propagate disambiguation symbols
+    through it. They are added on each state with non-epsilon output symbols
+    on at least one arc out of the state.
+
+    See also fstaddselfloops.pl from Kaldi. One difference is that
+    Kaldi uses OpenFst style FSTs and it has multiple final states.
+    This function uses k2 style FSTs and it does not need to add self-loops
+    to the final state.
+
+    The input label of a self-loop is `disambig_token`, while the output
+    label is `disambig_word`.
+
+    Args:
+      arcs:
+        A list-of-list. The sublist contains
+        `[src_state, dest_state, label, aux_label, score]`
+      disambig_token:
+        It is the token ID of the symbol `#0`.
+      disambig_word:
+        It is the word ID of the symbol `#0`.
+
+    Return:
+      Return new `arcs` containing self-loops.
+    """
+    states_needs_self_loops = set()
+    for arc in arcs:
+        src, dst, ilabel, olabel, score = arc
+        if olabel != 0:
+            states_needs_self_loops.add(src)
+
+    ans = []
+    for s in states_needs_self_loops:
+        ans.append([s, s, disambig_token, disambig_word, 0])
+
+    return arcs + ans
+
+
+def lexicon_to_fst(
+    lexicon: Lexicon,
+    token2id: Dict[str, int],
+    word2id: Dict[str, int],
+    sil_token: str = "!SIL",
+    sil_prob: float = 0.5,
+    need_self_loops: bool = False,
+) -> k2.Fsa:
+    """Convert a lexicon to an FST (in k2 format) with optional silence at
+    the beginning and end of each word.
+
+    Args:
+      lexicon:
+        The input lexicon. See also :func:`read_lexicon`
+      token2id:
+        A dict mapping tokens to IDs.
+      word2id:
+        A dict mapping words to IDs.
+      sil_token:
+        The silence token.
+      sil_prob:
+        The probability for adding a silence at the beginning and end
+        of the word.
+      need_self_loops:
+        If True, add self-loop to states with non-epsilon output symbols
+        on at least one arc out of the state. The input label for this
+        self loop is `token2id["#0"]` and the output label is `word2id["#0"]`.
+    Returns:
+      Return an instance of `k2.Fsa` representing the given lexicon.
+    """
+    assert sil_prob > 0.0 and sil_prob < 1.0
+    # CAUTION: we use score, i.e, negative cost.
+    sil_score = math.log(sil_prob)
+    no_sil_score = math.log(1.0 - sil_prob)
+
+    start_state = 0
+    loop_state = 1  # words enter and leave from here
+    sil_state = 2  # words terminate here when followed by silence; this state
+    # has a silence transition to loop_state.
+    next_state = 3  # the next un-allocated state, will be incremented as we go.
+    arcs = []
+
+    # assert token2id["<eps>"] == 0
+    # assert word2id["<eps>"] == 0
+
+    eps = 0
+    sil_token = word2id[sil_token]
+
+    arcs.append([start_state, loop_state, eps, eps, no_sil_score])
+    arcs.append([start_state, sil_state, eps, eps, sil_score])
+    arcs.append([sil_state, loop_state, sil_token, eps, 0])
+
+    for word, tokens in lexicon:
+        assert len(tokens) > 0, f"{word} has no pronunciations"
+        cur_state = loop_state
+
+        word = word2id[word]
+        tokens = [word2id[i] for i in tokens]
+
+        for i in range(len(tokens) - 1):
+            w = word if i == 0 else eps
+            arcs.append([cur_state, next_state, tokens[i], w, 0])
+
+            cur_state = next_state
+            next_state += 1
+
+        # now for the last token of this word
+        # It has two out-going arcs, one to the loop state,
+        # the other one to the sil_state.
+        i = len(tokens) - 1
+        w = word if i == 0 else eps
+        arcs.append([cur_state, loop_state, tokens[i], w, no_sil_score])
+        arcs.append([cur_state, sil_state, tokens[i], w, sil_score])
+
+    if need_self_loops:
+        disambig_token = word2id["#0"]
+        disambig_word = word2id["#0"]
+        arcs = add_self_loops(
+            arcs,
+            disambig_token=disambig_token,
+            disambig_word=disambig_word,
+        )
+
+    final_state = next_state
+    arcs.append([loop_state, final_state, -1, -1, 0])
+    arcs.append([final_state])
+
+    arcs = sorted(arcs, key=lambda arc: arc[0])
+    arcs = [[str(i) for i in arc] for arc in arcs]
+    arcs = [" ".join(arc) for arc in arcs]
+    arcs = "\n".join(arcs)
+
+    fsa = k2.Fsa.from_str(arcs, acceptor=False)
+    return fsa
+
+
+def main():
+    out_dir = Path("data/lm")
+    lexicon_filenames = [out_dir / "words_frames.txt", out_dir / "words_transcript.txt"]
+    names = ["frames", "transcript"]
+    sil_token = "!SIL"
+    sil_prob = 0.5
+
+    for name, lexicon_filename in zip(names, lexicon_filenames):
+      lexicon = read_lexicon(lexicon_filename)
+      tokens = get_words(lexicon)
+      words = get_words(lexicon)
+      new_lexicon = []
+      for lexicon_item in lexicon:
+          new_lexicon.append((lexicon_item[0], [lexicon_item[0]]))
+      lexicon = new_lexicon
+
+      lexicon_disambig, max_disambig = add_disambig_symbols(lexicon)
+
+      for i in range(max_disambig + 1):
+          disambig = f"#{i}"
+          assert disambig not in tokens
+          tokens.append(f"#{i}")
+
+      tokens = ["<eps>"] + tokens
+      words = ['eps'] + words + ["#0", "!SIL"]
+
+      token2id = generate_id_map(tokens)
+      word2id = generate_id_map(words)
+
+      write_mapping(out_dir / ("tokens_" + name + ".txt"), token2id)
+      write_mapping(out_dir / ("words_" + name + ".txt"), word2id)
+      write_lexicon(out_dir / ("lexicon_disambig_" + name + ".txt"), lexicon_disambig)
+
+      L = lexicon_to_fst(
+          lexicon,
+          token2id=word2id,
+          word2id=word2id,
+          sil_token=sil_token,
+          sil_prob=sil_prob,
+      )
+
+      L_disambig = lexicon_to_fst(
+          lexicon_disambig,
+          token2id=word2id,
+          word2id=word2id,
+          sil_token=sil_token,
+          sil_prob=sil_prob,
+          need_self_loops=True,
+      )
+      torch.save(L.as_dict(), out_dir / ("L_" + name + ".pt"))
+      torch.save(L_disambig.as_dict(), out_dir / ("L_disambig_" + name + ".pt"))
+
+      if False:
+          # Just for debugging, will remove it
+          L.labels_sym = k2.SymbolTable.from_file(out_dir / "tokens.txt")
+          L.aux_labels_sym = k2.SymbolTable.from_file(out_dir / "words.txt")
+          L_disambig.labels_sym = L.labels_sym
+          L_disambig.aux_labels_sym = L.aux_labels_sym
+          L.draw(out_dir / "L.png", title="L")
+          L_disambig.draw(out_dir / "L_disambig.png", title="L_disambig")
+
+
+main()
diff --git a/egs/slu/prepare.sh b/egs/slu/prepare.sh
new file mode 100755
index 000000000..ae8869aad
--- /dev/null
+++ b/egs/slu/prepare.sh
@@ -0,0 +1,100 @@
+#!/usr/bin/env bash
+
+# fix segmentation fault reported in https://github.com/k2-fsa/icefall/issues/674
+export PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=python
+
+set -eou pipefail
+
+stage=3
+stop_stage=5
+
+data_dir=/home/xli257/slu/fluent_speech_commands_dataset
+
+lang_dir=data/lang_phone
+lm_dir=data/lm
+
+. shared/parse_options.sh || exit 1
+
+mkdir -p $lang_dir
+mkdir -p $lm_dir
+
+log() {
+  # This function is from espnet
+  local fname=${BASH_SOURCE[1]##*/}
+  echo -e "$(date '+%Y-%m-%d %H:%M:%S') (${fname}:${BASH_LINENO[0]}:${FUNCNAME[1]}) $*"
+}
+
+log "data_dir: $data_dir"
+
+if [ $stage -le 1 ] && [ $stop_stage -ge 1 ]; then
+  log "Stage 1: Prepare slu manifest"
+  mkdir -p data/manifests
+  lhotse prepare slu $data_dir data/manifests
+fi
+
+if [ $stage -le 2 ] && [ $stop_stage -ge 2 ]; then
+  log "Stage 2: Compute fbank for yesno"
+  mkdir -p data/fbank
+  python ./local/compute_fbank_slu.py
+fi
+
+if [ $stage -le 3 ] && [ $stop_stage -ge 3 ]; then
+  log "Stage 3: Prepare lang"
+  # NOTE: "<UNK> SIL" is added for implementation convenience
+  # as the graph compiler code requires that there is a OOV word
+  # in the lexicon.
+  python ./local/generate_lexicon.py $data_dir $lm_dir
+fi
+
+if [ $stage -le 4 ] && [ $stop_stage -ge 4 ]; then
+  log "Stage 4: Train LM"
+  # We use a unigram G
+  ./shared/make_kn_lm.py \
+    -ngram-order 1 \
+    -text $lm_dir/words_transcript.txt \
+    -lm $lm_dir/G_transcript.arpa
+
+  ./shared/make_kn_lm.py \
+    -ngram-order 1 \
+    -text $lm_dir/words_frames.txt \
+    -lm $lm_dir/G_frames.arpa
+
+  python ./local/prepare_lang.py
+
+  if [ ! -f $lm_dir/G_transcript.fst.txt ]; then
+    python -m kaldilm \
+      --read-symbol-table="$lm_dir/words_transcript.txt" \
+      $lm_dir/G_transcript.arpa > $lm_dir/G_transcript.fst.txt
+  fi
+
+  if [ ! -f $lm_dir/G_frames.fst.txt ]; then
+    python -m kaldilm \
+      --read-symbol-table="$lm_dir/words_frames.txt" \
+      $lm_dir/G_frames.arpa > $lm_dir/G_frames.fst.txt
+  fi
+
+  mkdir -p $lm_dir/frames
+  mkdir -p $lm_dir/transcript
+
+  chmod -R +777 .
+
+  for i in G_frames.arpa G_frames.fst.txt L_disambig_frames.pt L_frames.pt lexicon_disambig_frames.txt tokens_frames.txt words_frames.txt;
+  do
+    j=${i//"_frames"/}
+    mv "$lm_dir/$i" $lm_dir/frames/$j
+  done
+
+  for i in G_transcript.arpa G_transcript.fst.txt L_disambig_transcript.pt L_transcript.pt lexicon_disambig_transcript.txt tokens_transcript.txt words_transcript.txt;
+  do
+    j=${i//"_transcript"/}
+    mv "$lm_dir/$i" $lm_dir/transcript/$j
+  done
+fi
+
+
+if [ $stage -le 5 ] && [ $stop_stage -ge 5 ]; then
+  log "Stage 5: Compile HLG"
+  ./local/compile_hlg.py --lang-dir $lm_dir/frames
+  ./local/compile_hlg.py --lang-dir $lm_dir/transcript
+
+fi
diff --git a/egs/slu/shared b/egs/slu/shared
new file mode 120000
index 000000000..32a374a7f
--- /dev/null
+++ b/egs/slu/shared
@@ -0,0 +1 @@
+../../icefall/shared/
\ No newline at end of file
diff --git a/icefall/shared/make_kn_lm.py b/icefall/shared/make_kn_lm.py
index 7150297d6..22bff9286 100755
--- a/icefall/shared/make_kn_lm.py
+++ b/icefall/shared/make_kn_lm.py
@@ -33,7 +33,7 @@ parser.add_argument(
     "-ngram-order",
     type=int,
     default=4,
-    choices=[2, 3, 4, 5, 6, 7],
+    choices=[1, 2, 3, 4, 5, 6, 7],
     help="Order of n-gram",
 )
 parser.add_argument("-text", type=str, default=None, help="Path to the corpus file")
@@ -105,7 +105,7 @@ class NgramCounts:
     # do as follows: self.counts[3][[5,6,7]][8] += 1.0 where the [3] indexes an
     # array, the [[5,6,7]] indexes a dict, and the [8] indexes a dict.
     def __init__(self, ngram_order, bos_symbol="<s>", eos_symbol="</s>"):
-        assert ngram_order >= 2
+        # assert ngram_order >= 2
 
         self.ngram_order = ngram_order
         self.bos_symbol = bos_symbol
@@ -169,7 +169,7 @@ class NgramCounts:
         with open(filename, encoding=default_encoding) as fp:
             for line in fp:
                 line = line.strip(strip_chars)
-                self.add_raw_counts_from_line(line)
+                self.add_raw_counts_from_line(line.split()[0])
                 lines_processed += 1
         if lines_processed == 0 or args.verbose > 0:
             print(