Theoretical foundations of software systems
Research Article
Checking Bisimulation Equivalence of Formal Game-Mechanic Models with Guard Conditions and Weighted Transitions
Vlada Vladimirovna Kugurakova
| Kazan Federal University, Kazan, Russia | |
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Abstract.
This paper addresses the formal equivalence checking of two implementations of the same game mechanic.
Such a task arises in game logic refactoring, comparison of independent implementations of one specification, and verification of balancing transformations.
The formal representation of such mechanics is based on the GD-FST
(Game Design Finite State Transducer) model.
The standard verification-theoretic approach of bisimulation is not directly applicable here, since GD-FST edges carry not mere labels but pairs
(guard condition, weight), which generates a novel non-trivial transition-matching problem.
The contribution is as follows:
\begin{enumerate}
\item a definition of bisimulation equivalence for GD-FST transducers is introduced, accounting for the edge structure of the formalism;
\item an algorithm for checking bisimulation equivalence is proposed, constructed by adapting the classical Kanellakis–Smolka partition refinement;
\item soundness and completeness of the algorithm are proved.
\end{enumerate}
The practical significance of the result lies in enabling automatic verification that refactoring or balancing transformation of a game mechanic does not alter its observable behaviour.
The proposed apparatus is applicable not only to game mechanics, but also to other rule-governed systems with guard conditions and numerical weights. (In Russian).
Keywords: bisimulation equivalence, GD-FST, game mechanics, formal verification, Kanellakis–Smolka algorithm, Hopcroft partition, temporal logic
MSC-2020
68Q85; 68N30, 03B44For citation: Vlada V. Kugurakova. Checking Bisimulation Equivalence of Formal Game-Mechanic Models with Guard Conditions and Weighted Transitions. Program Systems: Theory and Applications, 2026, 17:3, pp. 163–190. (In Russ.). https://psta.psiras.ru/2026/3_163-190.
Full text of article (PDF): https://psta.psiras.ru/read/psta2026_3_163-190.pdf.
The article was submitted 13.07.2026; approved after reviewing 04.08.2026; accepted for publication 17.08.2026; published online 15.09.2026.