The surprizing complexity of generalized reachability games

Games on graphs provide a natural and powerful model for reactive systems. In this paper, we consider generalized reachability objectives, defined as conjunctions of reachability objectives. We first prove that deciding the winner in such games is $\PSPACE$-complete, although it is fixed-parameter tractable with the number of reachability objectives as parameter. Moreover, we consider the memory requirements for both players and give matching upper and lower bounds on the size of winning strategies. In order to allow more efficient algorithms, we consider subclasses of generalized reachability games. We show that bounding the size of the reachability sets gives two natural subclasses where deciding the winner can be done efficiently.

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Field Value
Source https://hal.science/hal-00525762
Author Fijalkow, Nathanaël, Horn, Florian
Maintainer CCSD
Last Updated November 7, 2026, 08:36 (UTC)
Created November 7, 2026, 08:36 (UTC)
Identifier hal-00525762
Language en
Rights https://about.hal.science/hal-authorisation-v1/
contributor Laboratoire d'informatique Algorithmique : Fondements et Applications (LIAFA) ; Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
creator Fijalkow, Nathanaël
date 2010-10-12T00:00:00
harvest_object_id 67bdca4c-5db4-4f2f-ba04-15dc21ec9489
harvest_source_id 3374d638-d20b-4672-ba96-a23232d55657
harvest_source_title test moissonnage SELUNE
metadata_modified 2025-03-17T00:00:00
relation info:eu-repo/semantics/altIdentifier/arxiv/1010.2420
set_spec type:UNDEFINED