Analyzing Value Functions of States in Parametric Markov Chains

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Engelen, Kasper, Pérez, Guillermo A., Rao, Shrisha
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913807967715328
author Engelen, Kasper
Pérez, Guillermo A.
Rao, Shrisha
author_facet Engelen, Kasper
Pérez, Guillermo A.
Rao, Shrisha
contents Parametric Markov chains (pMC) are used to model probabilistic systems with unknown or partially known probabilities. Although (universal) pMC verification for reachability properties is known to be coETR-complete, there have been efforts to approach it using potentially easier-to-check properties such as asking whether the pMC is monotonic in certain parameters. In this paper, we first reduce monotonicity to asking whether the reachability probability from a given state is never less than that of another given state. Recent results for the latter property imply an efficient algorithm to collapse same-value equivalence classes, which in turn preserves verification results and monotonicity. We implement our algorithm to collapse "trivial" equivalence classes in the pMC and show empirical evidence for the following: First, the collapse gives reductions in size for some existing benchmarks and significant reductions on some custom benchmarks; Second, the collapse speeds up existing algorithms to check monotonicity and parameter lifting, and hence can be used as a fast pre-processing step in practice.
format Preprint
id arxiv_https___arxiv_org_abs_2504_17020
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Analyzing Value Functions of States in Parametric Markov Chains
Engelen, Kasper
Pérez, Guillermo A.
Rao, Shrisha
Logic in Computer Science
Artificial Intelligence
Parametric Markov chains (pMC) are used to model probabilistic systems with unknown or partially known probabilities. Although (universal) pMC verification for reachability properties is known to be coETR-complete, there have been efforts to approach it using potentially easier-to-check properties such as asking whether the pMC is monotonic in certain parameters. In this paper, we first reduce monotonicity to asking whether the reachability probability from a given state is never less than that of another given state. Recent results for the latter property imply an efficient algorithm to collapse same-value equivalence classes, which in turn preserves verification results and monotonicity. We implement our algorithm to collapse "trivial" equivalence classes in the pMC and show empirical evidence for the following: First, the collapse gives reductions in size for some existing benchmarks and significant reductions on some custom benchmarks; Second, the collapse speeds up existing algorithms to check monotonicity and parameter lifting, and hence can be used as a fast pre-processing step in practice.
title Analyzing Value Functions of States in Parametric Markov Chains
topic Logic in Computer Science
Artificial Intelligence
url https://arxiv.org/abs/2504.17020