---
OA_place: publisher
OA_type: hybrid
_id: '19743'
abstract:
- lang: eng
  text: The possibility of errors in human-engineered formal verification software,
    such as model checkers, poses a serious threat to the purpose of these tools.
    An established approach to mitigate this problem are certificates—lightweight,
    easy-to-check proofs of the verification results. In this paper, we develop novel
    certificates for model checking of Markov decision processes (MDPs) with quantitative
    reachability and expected reward properties. Our approach is conceptually simple
    and relies almost exclusively on elementary fixed point theory. Our certificates
    work for arbitrary finite MDPs and can be readily computed with little overhead
    using standard algorithms. We formalize the soundness of our certificates in Isabelle/HOL
    and provide a formally verified certificate checker. Moreover, we augment existing
    algorithms in the probabilistic model checker Storm with the ability to produce
    certificates and demonstrate practical applicability by conducting the first formal
    certification of the reference results in the Quantitative Verification Benchmark
    Set.
acknowledgement: This project has received funding from the ERC CoG 863818 (ForM-SMArt),
  the Austrian Science Fund (FWF) 10.55776/COE12, a KI-Starter grant from the Ministerium
  für Kultur und Wissenschaft NRW, the DFG RTG 378803395 (ConVeY), the EU’s Horizon
  2020 research and innovation programmes under the Marie Sklodowska-Curie grant agreement
  Nos. 101034413 (IST-BRIDGE) and 101008233 (MISSION), and the DFG RTG 2236 (UnRAVeL).
  Experiments were performed with computing resources granted by RWTH Aachen University
  under project rwth1632.
alternative_title:
- LNCS
article_processing_charge: No
arxiv: 1
author:
- first_name: Krishnendu
  full_name: Chatterjee, Krishnendu
  id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87
  last_name: Chatterjee
  orcid: 0000-0002-4561-241X
- first_name: Tim
  full_name: Quatmann, Tim
  last_name: Quatmann
- first_name: Maximilian
  full_name: Schäffeler, Maximilian
  last_name: Schäffeler
- first_name: Maximilian
  full_name: Weininger, Maximilian
  id: 02ab0197-cc70-11ed-ab61-918e71f56881
  last_name: Weininger
  orcid: 0000-0002-0163-2152
- first_name: Tobias
  full_name: Winkler, Tobias
  last_name: Winkler
- first_name: Daniel
  full_name: Zilken, Daniel
  id: d8ebc24a-3f98-11f0-9044-8296d4f39ab3
  last_name: Zilken
citation:
  ama: 'Chatterjee K, Quatmann T, Schäffeler M, Weininger M, Winkler T, Zilken D.
    Fixed point certificates for reachability and expected rewards in MDPs. In: <i>31st
    International Conference on Tools and Algorithms for the Construction and Analysis
    of Systems</i>. Vol 15697. Springer Nature; 2025:130-151. doi:<a href="https://doi.org/10.1007/978-3-031-90653-4_7">10.1007/978-3-031-90653-4_7</a>'
  apa: 'Chatterjee, K., Quatmann, T., Schäffeler, M., Weininger, M., Winkler, T.,
    &#38; Zilken, D. (2025). Fixed point certificates for reachability and expected
    rewards in MDPs. In <i>31st International Conference on Tools and Algorithms for
    the Construction and Analysis of Systems</i> (Vol. 15697, pp. 130–151). Hamilton,
    ON, Canada: Springer Nature. <a href="https://doi.org/10.1007/978-3-031-90653-4_7">https://doi.org/10.1007/978-3-031-90653-4_7</a>'
  chicago: Chatterjee, Krishnendu, Tim Quatmann, Maximilian Schäffeler, Maximilian
    Weininger, Tobias Winkler, and Daniel Zilken. “Fixed Point Certificates for Reachability
    and Expected Rewards in MDPs.” In <i>31st International Conference on Tools and
    Algorithms for the Construction and Analysis of Systems</i>, 15697:130–51. Springer
    Nature, 2025. <a href="https://doi.org/10.1007/978-3-031-90653-4_7">https://doi.org/10.1007/978-3-031-90653-4_7</a>.
  ieee: K. Chatterjee, T. Quatmann, M. Schäffeler, M. Weininger, T. Winkler, and D.
    Zilken, “Fixed point certificates for reachability and expected rewards in MDPs,”
    in <i>31st International Conference on Tools and Algorithms for the Construction
    and Analysis of Systems</i>, Hamilton, ON, Canada, 2025, vol. 15697, pp. 130–151.
  ista: 'Chatterjee K, Quatmann T, Schäffeler M, Weininger M, Winkler T, Zilken D.
    2025. Fixed point certificates for reachability and expected rewards in MDPs.
    31st International Conference on Tools and Algorithms for the Construction and
    Analysis of Systems. TACAS: Tools and Algorithms for the Construction and Analysis
    of Systems, LNCS, vol. 15697, 130–151.'
  mla: Chatterjee, Krishnendu, et al. “Fixed Point Certificates for Reachability and
    Expected Rewards in MDPs.” <i>31st International Conference on Tools and Algorithms
    for the Construction and Analysis of Systems</i>, vol. 15697, Springer Nature,
    2025, pp. 130–51, doi:<a href="https://doi.org/10.1007/978-3-031-90653-4_7">10.1007/978-3-031-90653-4_7</a>.
  short: K. Chatterjee, T. Quatmann, M. Schäffeler, M. Weininger, T. Winkler, D. Zilken,
    in:, 31st International Conference on Tools and Algorithms for the Construction
    and Analysis of Systems, Springer Nature, 2025, pp. 130–151.
conference:
  end_date: 2025-05-08
  location: Hamilton, ON, Canada
  name: 'TACAS: Tools and Algorithms for the Construction and Analysis of Systems'
  start_date: 2025-05-03
corr_author: '1'
date_created: 2025-05-25T22:17:09Z
date_published: 2025-05-01T00:00:00Z
date_updated: 2026-09-16T06:57:17Z
day: '01'
ddc:
- '000'
department:
- _id: KrCh
doi: 10.1007/978-3-031-90653-4_7
ec_funded: 1
external_id:
  arxiv:
  - '2501.11467'
file:
- access_level: open_access
  checksum: 64b7f46ef05649b87b827248045c7645
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  creator: dernst
  date_created: 2025-06-02T10:49:52Z
  date_updated: 2025-06-02T10:49:52Z
  file_id: '19772'
  file_name: 2025_TACAS_ChatterjeeKrish.pdf
  file_size: 732136
  relation: main_file
  success: 1
file_date_updated: 2025-06-02T10:49:52Z
fulldoi: https://doi.org/10.1007/978-3-031-90653-4_7
has_accepted_license: '1'
intvolume: '     15697'
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '05'
oa: 1
oa_version: Published Version
page: 130-151
project:
- _id: 0599E47C-7A3F-11EA-A408-12923DDC885E
  call_identifier: H2020
  grant_number: '863818'
  name: 'Formal Methods for Stochastic Models: Algorithms and Applications'
- _id: fc2ed2f7-9c52-11eb-aca3-c01059dda49c
  call_identifier: H2020
  grant_number: '101034413'
  name: 'IST-BRIDGE: International postdoctoral program'
- _id: 4029cfc7-b034-11f1-9e55-88ab2ff3b6ee
  grant_number: COE12
  name: Bilateral Artificial Intelligence (Chatterjee)
publication: 31st International Conference on Tools and Algorithms for the Construction
  and Analysis of Systems
publication_identifier:
  eissn:
  - 1611-3349
  isbn:
  - '9783031906527'
  issn:
  - 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
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    status: public
scopus_import: '1'
status: public
title: Fixed point certificates for reachability and expected rewards in MDPs
tmp:
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  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
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  short: CC BY (4.0)
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 15697
year: '2025'
...
---
OA_place: publisher
OA_type: hybrid
_id: '19740'
abstract:
- lang: eng
  text: Two standard models for probabilistic systems are Markov chains (MCs) and
    Markov decision processes (MDPs). Classic objectives for such probabilistic models
    for control and planning problems are reachability and stochastic shortest path.
    The widely studied algorithmic approach for these problems is the Value Iteration
    (VI) algorithm which iteratively applies local updates called Bellman updates.
    There are many practical approaches for VI in the literature but they all require
    exponentially many Bellman updates for MCs in the worst case. A preprocessing
    step is an algorithm that is discrete, graph-theoretical, and requires linear
    space. An important open question is whether, after a polynomial-time preprocessing,
    VI can be achieved with sub-exponentially many Bellman updates. In this work,
    we present a new approach for VI based on guessing values. Our theoretical contributions
    are twofold. First, for MCs, we present an almost-linear-time preprocessing algorithm
    after which, along with guessing values, VI requires only subexponentially many
    Bellman updates. Second, we present an improved analysis of the speed of convergence
    of VI for MDPs. Finally, we present a practical algorithm for MDPs based on our
    new approach. Experimental results show that our approach provides a considerable
    improvement over existing VI-based approaches on several benchmark examples from
    the literature.
acknowledgement: This research was partially supported by the ERC CoG 863818 (ForM-SMArt)
  grant and Austrian Science Fund (FWF) 10.55776/COE12 grant.
alternative_title:
- LNCS
article_processing_charge: No
arxiv: 1
author:
- first_name: Krishnendu
  full_name: Chatterjee, Krishnendu
  id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87
  last_name: Chatterjee
  orcid: 0000-0002-4561-241X
- first_name: Mahdi
  full_name: Jafariraviz, Mahdi
  last_name: Jafariraviz
- first_name: Raimundo J
  full_name: Saona Urmeneta, Raimundo J
  id: BD1DF4C4-D767-11E9-B658-BC13E6697425
  last_name: Saona Urmeneta
  orcid: 0000-0001-5103-038X
- first_name: Jakub
  full_name: Svoboda, Jakub
  id: 130759D2-D7DD-11E9-87D2-DE0DE6697425
  last_name: Svoboda
  orcid: 0000-0002-1419-3267
citation:
  ama: 'Chatterjee K, Jafariraviz M, Saona Urmeneta RJ, Svoboda J. Value iteration
    with guessing for Markov chains and Markov decision processes. In: <i>31st International
    Conference on Tools and Algorithms for the Construction and Analysis of Systems</i>.
    Vol 15697. Springer Nature; 2025:217-236. doi:<a href="https://doi.org/10.1007/978-3-031-90653-4_11">10.1007/978-3-031-90653-4_11</a>'
  apa: 'Chatterjee, K., Jafariraviz, M., Saona Urmeneta, R. J., &#38; Svoboda, J.
    (2025). Value iteration with guessing for Markov chains and Markov decision processes.
    In <i>31st International Conference on Tools and Algorithms for the Construction
    and Analysis of Systems</i> (Vol. 15697, pp. 217–236). Hamilton, ON, Canada: Springer
    Nature. <a href="https://doi.org/10.1007/978-3-031-90653-4_11">https://doi.org/10.1007/978-3-031-90653-4_11</a>'
  chicago: Chatterjee, Krishnendu, Mahdi Jafariraviz, Raimundo J Saona Urmeneta, and
    Jakub Svoboda. “Value Iteration with Guessing for Markov Chains and Markov Decision
    Processes.” In <i>31st International Conference on Tools and Algorithms for the
    Construction and Analysis of Systems</i>, 15697:217–36. Springer Nature, 2025.
    <a href="https://doi.org/10.1007/978-3-031-90653-4_11">https://doi.org/10.1007/978-3-031-90653-4_11</a>.
  ieee: K. Chatterjee, M. Jafariraviz, R. J. Saona Urmeneta, and J. Svoboda, “Value
    iteration with guessing for Markov chains and Markov decision processes,” in <i>31st
    International Conference on Tools and Algorithms for the Construction and Analysis
    of Systems</i>, Hamilton, ON, Canada, 2025, vol. 15697, pp. 217–236.
  ista: 'Chatterjee K, Jafariraviz M, Saona Urmeneta RJ, Svoboda J. 2025. Value iteration
    with guessing for Markov chains and Markov decision processes. 31st International
    Conference on Tools and Algorithms for the Construction and Analysis of Systems.
    TACAS: Tools and Algorithms for the Construction and Analysis of Systems, LNCS,
    vol. 15697, 217–236.'
  mla: Chatterjee, Krishnendu, et al. “Value Iteration with Guessing for Markov Chains
    and Markov Decision Processes.” <i>31st International Conference on Tools and
    Algorithms for the Construction and Analysis of Systems</i>, vol. 15697, Springer
    Nature, 2025, pp. 217–36, doi:<a href="https://doi.org/10.1007/978-3-031-90653-4_11">10.1007/978-3-031-90653-4_11</a>.
  short: K. Chatterjee, M. Jafariraviz, R.J. Saona Urmeneta, J. Svoboda, in:, 31st
    International Conference on Tools and Algorithms for the Construction and Analysis
    of Systems, Springer Nature, 2025, pp. 217–236.
conference:
  end_date: 2025-05-08
  location: Hamilton, ON, Canada
  name: 'TACAS: Tools and Algorithms for the Construction and Analysis of Systems'
  start_date: 2025-05-03
corr_author: '1'
date_created: 2025-05-25T22:17:06Z
date_published: 2025-05-01T00:00:00Z
date_updated: 2026-09-16T06:56:56Z
day: '01'
ddc:
- '000'
department:
- _id: KrCh
doi: 10.1007/978-3-031-90653-4_11
ec_funded: 1
external_id:
  arxiv:
  - '2505.06769'
file:
- access_level: open_access
  checksum: 45da6efbcbed20aada16c48c8e55e2d6
  content_type: application/pdf
  creator: dernst
  date_created: 2025-06-02T07:31:12Z
  date_updated: 2025-06-02T07:31:12Z
  file_id: '19767'
  file_name: 2025_TACAS_Chatterjee.pdf
  file_size: 557481
  relation: main_file
  success: 1
file_date_updated: 2025-06-02T07:31:12Z
fulldoi: https://doi.org/10.1007/978-3-031-90653-4_11
has_accepted_license: '1'
intvolume: '     15697'
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
page: 217-236
project:
- _id: 0599E47C-7A3F-11EA-A408-12923DDC885E
  call_identifier: H2020
  grant_number: '863818'
  name: 'Formal Methods for Stochastic Models: Algorithms and Applications'
- _id: 4029cfc7-b034-11f1-9e55-88ab2ff3b6ee
  grant_number: COE12
  name: Bilateral Artificial Intelligence (Chatterjee)
publication: 31st International Conference on Tools and Algorithms for the Construction
  and Analysis of Systems
publication_identifier:
  eissn:
  - 1611-3349
  isbn:
  - '9783031906527'
  issn:
  - 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Value iteration with guessing for Markov chains and Markov decision processes
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
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...
---
OA_place: publisher
OA_type: hybrid
_id: '19744'
abstract:
- lang: eng
  text: We consider the problem of refuting equivalence of probabilistic programs,
    i.e., the problem of proving that two probabilistic programs induce different
    output distributions. We study this problem in the context of programs with conditioning
    (i.e., with observe and score statements), where the output distribution is conditioned
    by the event that all the observe statements along a run evaluate to true, and
    where the probability densities of different runs may be updated via the score
    statements. Building on a recent work on programs without conditioning, we present
    a new equivalence refutation method for programs with conditioning. Our method
    is based on weighted restarting, a novel transformation of probabilistic programs
    with conditioning to the output equivalent probabilistic programs without conditioning
    that we introduce in this work. Our method is the first to be both a) fully automated,
    and b) providing provably correct answers. We demonstrate the applicability of
    our method on a set of programs from the probabilistic inference literature.
acknowledgement: This work was partially supported by ERC CoG 863818 (ForM-SMArt)
  and Austrian Science Fund (FWF) 10.55776/COE12. Petr Novotný is supported by the
  Czech Science Foundation grant no. GA23-06963S.
alternative_title:
- LNCS
article_processing_charge: No
arxiv: 1
author:
- first_name: Krishnendu
  full_name: Chatterjee, Krishnendu
  id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87
  last_name: Chatterjee
  orcid: 0000-0002-4561-241X
- first_name: Ehsan
  full_name: Kafshdar Goharshadi, Ehsan
  id: 103b4fa0-896a-11ed-bdf8-87b697bef40d
  last_name: Kafshdar Goharshadi
  orcid: 0000-0002-8595-0587
- first_name: Petr
  full_name: Novotný, Petr
  id: 3CC3B868-F248-11E8-B48F-1D18A9856A87
  last_name: Novotný
- first_name: Dorde
  full_name: Zikelic, Dorde
  id: 294AA7A6-F248-11E8-B48F-1D18A9856A87
  last_name: Zikelic
  orcid: 0000-0002-4681-1699
citation:
  ama: 'Chatterjee K, Goharshady E, Novotný P, Zikelic D. Refuting equivalence in
    probabilistic programs with conditioning. In: <i>31st International Conference
    on Tools and Algorithms for the Construction and Analysis of Systems</i>. Vol
    15697. Springer Nature; 2025:279-300. doi:<a href="https://doi.org/10.1007/978-3-031-90653-4_14">10.1007/978-3-031-90653-4_14</a>'
  apa: 'Chatterjee, K., Goharshady, E., Novotný, P., &#38; Zikelic, D. (2025). Refuting
    equivalence in probabilistic programs with conditioning. In <i>31st International
    Conference on Tools and Algorithms for the Construction and Analysis of Systems</i>
    (Vol. 15697, pp. 279–300). Hamilton, ON, Canada: Springer Nature. <a href="https://doi.org/10.1007/978-3-031-90653-4_14">https://doi.org/10.1007/978-3-031-90653-4_14</a>'
  chicago: Chatterjee, Krishnendu, Ehsan Goharshady, Petr Novotný, and Dorde Zikelic.
    “Refuting Equivalence in Probabilistic Programs with Conditioning.” In <i>31st
    International Conference on Tools and Algorithms for the Construction and Analysis
    of Systems</i>, 15697:279–300. Springer Nature, 2025. <a href="https://doi.org/10.1007/978-3-031-90653-4_14">https://doi.org/10.1007/978-3-031-90653-4_14</a>.
  ieee: K. Chatterjee, E. Goharshady, P. Novotný, and D. Zikelic, “Refuting equivalence
    in probabilistic programs with conditioning,” in <i>31st International Conference
    on Tools and Algorithms for the Construction and Analysis of Systems</i>, Hamilton,
    ON, Canada, 2025, vol. 15697, pp. 279–300.
  ista: 'Chatterjee K, Goharshady E, Novotný P, Zikelic D. 2025. Refuting equivalence
    in probabilistic programs with conditioning. 31st International Conference on
    Tools and Algorithms for the Construction and Analysis of Systems. TACAS: Tools
    and Algorithms for the Construction and Analysis of Systems, LNCS, vol. 15697,
    279–300.'
  mla: Chatterjee, Krishnendu, et al. “Refuting Equivalence in Probabilistic Programs
    with Conditioning.” <i>31st International Conference on Tools and Algorithms for
    the Construction and Analysis of Systems</i>, vol. 15697, Springer Nature, 2025,
    pp. 279–300, doi:<a href="https://doi.org/10.1007/978-3-031-90653-4_14">10.1007/978-3-031-90653-4_14</a>.
  short: K. Chatterjee, E. Goharshady, P. Novotný, D. Zikelic, in:, 31st International
    Conference on Tools and Algorithms for the Construction and Analysis of Systems,
    Springer Nature, 2025, pp. 279–300.
conference:
  end_date: 2025-05-08
  location: Hamilton, ON, Canada
  name: 'TACAS: Tools and Algorithms for the Construction and Analysis of Systems'
  start_date: 2025-05-03
corr_author: '1'
date_created: 2025-05-25T22:17:10Z
date_published: 2025-05-01T00:00:00Z
date_updated: 2026-09-16T06:57:43Z
day: '01'
ddc:
- '000'
department:
- _id: KrCh
doi: 10.1007/978-3-031-90653-4_14
ec_funded: 1
external_id:
  arxiv:
  - '2501.06579'
file:
- access_level: open_access
  checksum: 7dcd85e7e753bfa994c10b3cf9ebc185
  content_type: application/pdf
  creator: dernst
  date_created: 2025-06-02T11:13:49Z
  date_updated: 2025-06-02T11:13:49Z
  file_id: '19773'
  file_name: 2025_TACAS_Chatterjee_Goharshadi.pdf
  file_size: 532181
  relation: main_file
  success: 1
file_date_updated: 2025-06-02T11:13:49Z
fulldoi: https://doi.org/10.1007/978-3-031-90653-4_14
has_accepted_license: '1'
intvolume: '     15697'
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
page: 279-300
project:
- _id: 0599E47C-7A3F-11EA-A408-12923DDC885E
  call_identifier: H2020
  grant_number: '863818'
  name: 'Formal Methods for Stochastic Models: Algorithms and Applications'
- _id: 4029cfc7-b034-11f1-9e55-88ab2ff3b6ee
  grant_number: COE12
  name: Bilateral Artificial Intelligence (Chatterjee)
publication: 31st International Conference on Tools and Algorithms for the Construction
  and Analysis of Systems
publication_identifier:
  eissn:
  - 1611-3349
  isbn:
  - '9783031906527'
  issn:
  - 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Refuting equivalence in probabilistic programs with conditioning
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
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  short: CC BY (4.0)
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 15697
year: '2025'
...
