English

Automata Linear Dynamic Logic on Finite Traces

Logic in Computer Science 2025-07-16 v6

Abstract

Temporal logics are widely used by the Formal Methods and AI communities. Linear Temporal Logic is a popular temporal logic and is valued for its ease of use as well as its balance between expressiveness and complexity. LTL is equivalent in expressiveness to Monadic First-Order Logic and satisfiability for LTL is PSPACE-complete. Linear Dynamic Logic (LDL), another temporal logic, is equivalent to Monadic Second-Order Logic, but its method of satisfiability checking cannot be applied to a nontrivial subset of LDL formulas. Here we introduce Automata Linear Dynamic Logic on Finite Traces (ALDL_f) and show that satisfiability for ALDL_f formulas is in PSPACE. A variant of Linear Dynamic Logic on Finite Traces (LDL_f), ALDL_f combines propositional logic with nondeterministic finite automata (NFA) to express temporal constraints. ALDLf_f is equivalent in expressiveness to Monadic Second-Order Logic. This is a gain in expressiveness over LTL at no cost.

Keywords

Cite

@article{arxiv.2108.12003,
  title  = {Automata Linear Dynamic Logic on Finite Traces},
  author = {Kevin W. Smith and Moshe Y. Vardi},
  journal= {arXiv preprint arXiv:2108.12003},
  year   = {2025}
}
R2 v1 2026-06-24T05:27:14.840Z