Papers › Ordered Neurons: Integrating Tree Structures into Recurrent Neural Networks

Ordered Neurons: Integrating Tree Structures into Recurrent Neural Networks

22 Oct 2018ICLR 2019 5arXiv:1810.09536archive 2025-07-28

Yikang Shen, Shawn Tan, Alessandro Sordoni, Aaron Courville

Natural language is hierarchically structured: smaller units (e.g., phrases) are nested within larger units (e.g., clauses). When a larger constituent ends, all of the smaller constituents that are nested within it must also be closed. While the standard LSTM architecture allows different neurons to track information at different time scales, it does not have an explicit bias towards modeling a hierarchy of constituents. This paper proposes to add such an inductive bias by ordering the neurons; a vector of master input and forget gates ensures that when a given neuron is updated, all the neurons that follow it in the ordering are also updated. Our novel recurrent architecture, ordered neurons LSTM (ON-LSTM), achieves good performance on four different tasks: language modeling, unsupervised parsing, targeted syntactic evaluation, and logical inference.

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Code

Syntology Ran 3 of 12 code samples harvested from 3 repositories linked to this paper; 9 have no recorded run. Of those that ran: 1 ran · honoured contract; 1 ran · our draft was wrong; 1 ran · fixture could not drive it.

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yikangshen/Ordered-Neurons officialmentioned in papermentioned on GitHubpytorch report
IanTheColder/ONLSTM-analysis mentioned on GitHubpytorchBSD-3-Clause report
TieDanCuihua/Hierarchical-Attention-Networks-for-Document-Classification-Tensorflow mentioned on GitHubtfnot reachable when probed 2026-09-18 — repositories for recent papers often appear after camera-ready report
TieDanCuihua/ORDERED-NEURONS-INTEGRATING-TREE-STRUCTURES-INTO-RECURRENT-NEURAL-NETWORKS--tensorflow mentioned on GitHubtfnot reachable when probed 2026-09-18 — repositories for recent papers often appear after camera-ready report
billptw/fasttrees mentioned on GitHubpytorchBSD-3-Clause report
whull/ONLSTM mentioned on GitHubtf report
zi-lin/on-lstm-tensorflow mentioned on GitHubtfApache-2.0 report

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Code Syntology ran Syntology

12 samples harvested; 3 ran; 1 honoured the contract we drafted; 9 have no recorded run. Read from Syntology's graph 2026-09-24; that is when this build read the record, not when the samples ran.

1ran · honoured contract
1ran · our draft was wrong
1ran · fixture could not drive it
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build_tree yikangshen/Ordered-Neurons/test_phrase_grammar.py official repository ran · fixture could not drive it fingerprinted BSD-3-Clause (permissive) · 2cdc4ed134986036 · report
cumsoftmax yikangshen/Ordered-Neurons/ON_LSTM.py official repository ran · our draft was wrong fingerprinted BSD-3-Clause (permissive) · 4b59eaae917b5a2d · report
repackage_hidden IanTheColder/ONLSTM-analysis/utils.py community (archive-listed) ran · honoured contract fingerprinted BSD-3-Clause (permissive) · 4372bb4533fd1936 · report
balance IanTheColder/ONLSTM-analysis/parse_comparison.py community (archive-listed) unverified BSD-3-Clause (permissive) · bef0350ba4dc9a48 · report
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cumsoftmax zi-lin/on-lstm-tensorflow/on_lstm_layer.py community (archive-listed) unverified Apache-2.0 (permissive) · 71364ee53326b360 · report
embedded_dropout IanTheColder/ONLSTM-analysis/embed_regularize.py community (archive-listed) unverified BSD-3-Clause (permissive) · 62d148258bdd054f · report
get_batch IanTheColder/ONLSTM-analysis/utils.py community (archive-listed) unverified BSD-3-Clause (permissive) · 6f3c8e0b36d76af7 · report
parenthesize IanTheColder/ONLSTM-analysis/parse_by_baseline.py community (archive-listed) unverified BSD-3-Clause (permissive) · 7e3df128e06d7869 · report
randomize_split IanTheColder/ONLSTM-analysis/parse_by_baseline.py community (archive-listed) unverified BSD-3-Clause (permissive) · 31b75ccedc2bc209 · report
roundup2 IanTheColder/ONLSTM-analysis/parse_comparison.py community (archive-listed) unverified BSD-3-Clause (permissive) · 219eb921a74ea62c · report
spaceify IanTheColder/ONLSTM-analysis/parse_comparison.py community (archive-listed) unverified BSD-3-Clause (permissive) · ed1c4f48a3e8e92e · report

Tasks

Constituency Grammar InductionInductive BiasLanguage ModelingLanguage Modelling

Results from the paper archive 2025-07-28

TaskDatasetModelMetricValueRank at snapshotLeaderboardReport
Constituency Grammar Induction PTB Diagnostic ECG Database ON-LSTM (tuned) Max F1 (WSJ) 50.0 #19 of 24 Archive leaderboard report
Constituency Grammar Induction PTB Diagnostic ECG Database ON-LSTM (tuned) Mean F1 (WSJ) 48.1 #19 of 24 Archive leaderboard report
Constituency Grammar Induction PTB Diagnostic ECG Database ON-LSTM Max F1 (WSJ) 49.4 #21 of 24 Archive leaderboard report
Constituency Grammar Induction PTB Diagnostic ECG Database ON-LSTM Max F1 (WSJ10) 66.8 #21 of 24 Archive leaderboard report
Constituency Grammar Induction PTB Diagnostic ECG Database ON-LSTM Mean F1 (WSJ) 47.7 #21 of 24 Archive leaderboard report
Constituency Grammar Induction PTB Diagnostic ECG Database ON-LSTM Mean F1 (WSJ10) 65.1 #21 of 24 Archive leaderboard report

Ranks are positions in the archive's leaderboards as they stood at the 2025-07-28 snapshot. Results published since then are not among these rows, so a rank here is not a current standing.

Methods

LSTMSigmoid ActivationTanh Activation

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