Search Results

Documents authored by Alsmann, Eric


Document
The Satisfiability Problem of Temporal-Spatial Logics over Quasi-Temporal Graphs

Authors: Eric Alsmann, Martin Lange, and Igor Semezies

Published in: OASIcs, Volume 146, 33rd International Symposium on Temporal Representation and Reasoning (TIME 2026)


Abstract
Temporal Graph Neural Networks (TGNN) are used to detect patterns in so-called temporal graphs (TG): graphs in which edges may be added or removed over time. Sälzer et al. suggested to study the expressive power of TGNNs through temporal-spatial logics, specifically the combination of the linear-time temporal logic LTL and modal logic K. In this paper we investigate the computational complexity of the satisfiability problem for this logic and its natural extension in which the LTL part is replaced by a linear-time μ-calculus, reflecting TGNNs' ability to recognise not just star-free (word) languages. We consider their interpretation over a more natural class of models which we call quasi-temporal graphs (QTG), relaxing certain conditions on the temporal evolutions of nodes that are indifferent to the logic. We formalise this by giving an adjusted notion of bisimulation which preserves satisfaction in these logics. It turns out that satisfiability over the class of QTGs is PSPACE-complete for the temporal-spatial logic based on LTL but becomes EXPTIME-complete when based on the μ-calculus. This is in contrast to the situation on words where both logics are PSPACE-complete. We also discuss consequences for the special satisfiability problems over the class of TGs.

Cite as

Eric Alsmann, Martin Lange, and Igor Semezies. The Satisfiability Problem of Temporal-Spatial Logics over Quasi-Temporal Graphs. In 33rd International Symposium on Temporal Representation and Reasoning (TIME 2026). Open Access Series in Informatics (OASIcs), Volume 146, pp. 8:1-8:16, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2026)


Copy BibTex To Clipboard

@InProceedings{alsmann_et_al:OASIcs.TIME.2026.8,
  author =	{Alsmann, Eric and Lange, Martin and Semezies, Igor},
  title =	{{The Satisfiability Problem of Temporal-Spatial Logics over Quasi-Temporal Graphs}},
  booktitle =	{33rd International Symposium on Temporal Representation and Reasoning (TIME 2026)},
  pages =	{8:1--8:16},
  series =	{Open Access Series in Informatics (OASIcs)},
  ISBN =	{978-3-95977-448-2},
  ISSN =	{2190-6807},
  year =	{2026},
  volume =	{146},
  editor =	{Orlandini, AndreA and Pinchinat, Sophie},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/OASIcs.TIME.2026.8},
  URN =		{urn:nbn:de:0030-drops-277049},
  doi =		{10.4230/OASIcs.TIME.2026.8},
  annote =	{Keywords: linear-time temporal logic, modal logic, temporal graphs, computational complexity, automated reasoning}
}
Document
Metric Linear-Time Temporal Logic with Strict First-Time Semantics

Authors: Eric Alsmann and Martin Lange

Published in: LIPIcs, Volume 355, 32nd International Symposium on Temporal Representation and Reasoning (TIME 2025)


Abstract
We introduce strict first-time semantics for the Until operator from linear-time temporal logic which makes assertions not just about some future moment but about the first time in the future that its argument should hold. We investigate Metric Linear-Time Temporal Logic under this interpretation in terms of expressive power, relative succinctness and computational complexity. While the expressiveness does not exceed that of pure LTL, there are properties definable in this logic which can only be expressed in LTL with exponentially larger formulas. Yet, we show that the complexity of the satisfiability problem remains PSPACE-complete which is in contrast to the EXPSPACE-completeness of Metric LTL. The motivation for this logic originates in a study of the expressive power of State Space Models, a recently proposed alternative to the popular transformer architectures in machine learning.

Cite as

Eric Alsmann and Martin Lange. Metric Linear-Time Temporal Logic with Strict First-Time Semantics. In 32nd International Symposium on Temporal Representation and Reasoning (TIME 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 355, pp. 3:1-3:14, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


Copy BibTex To Clipboard

@InProceedings{alsmann_et_al:LIPIcs.TIME.2025.3,
  author =	{Alsmann, Eric and Lange, Martin},
  title =	{{Metric Linear-Time Temporal Logic with Strict First-Time Semantics}},
  booktitle =	{32nd International Symposium on Temporal Representation and Reasoning (TIME 2025)},
  pages =	{3:1--3:14},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-401-7},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{355},
  editor =	{Vidal, Thierry and Wa{\l}\k{e}ga, Przemys{\l}aw Andrzej},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.TIME.2025.3},
  URN =		{urn:nbn:de:0030-drops-244491},
  doi =		{10.4230/LIPIcs.TIME.2025.3},
  annote =	{Keywords: linear-time temporal logic, metric temporal logic, computational complexity, Streett automata}
}
Document
Real-Time Higher-Order Recursion Schemes

Authors: Eric Alsmann and Florian Bruse

Published in: LIPIcs, Volume 318, 31st International Symposium on Temporal Representation and Reasoning (TIME 2024)


Abstract
Higher-Order Recursion Schemes (HORS) have long been studied as a tool to model functional programs. Model-checking the tree generated by a HORS of order k against a parity automaton is known to be k-EXPTIME-complete. This paper introduces timed HORS, a real-time version of HORS in the sense of Alur/Dill'90, to be model-checked against a pair of a parity automaton and a timed automaton. We show that adding dense linear time to the notion of recursion schemes adds one exponential to the cost of model-checking, i.e., model-checking a timed HORS of order k can be done in (k+1)-EXPTIME. This is shown by an adaption of the region-graph construction known from the model-checking of timed CTL. We also obtain a hardness result for k = 1, but we strongly conjecture that it holds for all k. This result is obtained by encoding runs of 2-EXPTIME Turing machines into the trees generated by timed HORS.

Cite as

Eric Alsmann and Florian Bruse. Real-Time Higher-Order Recursion Schemes. In 31st International Symposium on Temporal Representation and Reasoning (TIME 2024). Leibniz International Proceedings in Informatics (LIPIcs), Volume 318, pp. 16:1-16:20, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2024)


Copy BibTex To Clipboard

@InProceedings{alsmann_et_al:LIPIcs.TIME.2024.16,
  author =	{Alsmann, Eric and Bruse, Florian},
  title =	{{Real-Time Higher-Order Recursion Schemes}},
  booktitle =	{31st International Symposium on Temporal Representation and Reasoning (TIME 2024)},
  pages =	{16:1--16:20},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-349-2},
  ISSN =	{1868-8969},
  year =	{2024},
  volume =	{318},
  editor =	{Sala, Pietro and Sioutis, Michael and Wang, Fusheng},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.TIME.2024.16},
  URN =		{urn:nbn:de:0030-drops-212236},
  doi =		{10.4230/LIPIcs.TIME.2024.16},
  annote =	{Keywords: Timed Automata, Higher-Order Recursion Schemes, Tree Automata}
}

Any Issues?
X

Feedback on the Current Page

CAPTCHA

Thanks for your feedback!

Feedback submitted to Dagstuhl Publishing

Could not send message

Please try again later or send an E-mail