Benchmark

non-incremental/QF_NRA/20240407-pPDA-Chiari-Pontiggia-Winkler/past/sqrt2by2_bern_PRAY.smt2

Publications:
  [1] Tobias Winkler, Joost-Pieter Katoen: On Certificates, Expected Runtimes, and Termination in Probabilistic Pushdown Automata. LICS 2023: 1-13

This benchmark encodes positive almost sure termination (PAST; reaching the empty stack in finite expected time) of a probabilistic pushdown automaton (pPDA) modelling a symmetric random walk on the non-negative integers. The walk is started at position 1 and flips a bit every time it moves towards 0. When it reaches 0, the bit is distributed according to a Bernoulli-sqrt(2)/2 distribution. However, 0 is only reached after infinitely many steps on average.

The SMT formula results from applying Theorem 8 from [1]. The SMT formula is SAT iff the automaton is PAST.
Benchmark
Size2399
Compressed Size909
License Creative Commons Attribution 4.0 International (CC-BY-4.0)
Categoryindustrial
First Occurrence2024-07-22
Generated ByTobias Winkler
Generated On2024-04-07 00:00:00
GeneratorPRAY - Probabilistic Recursion Analyzer (https://doi.org/10.5281/zenodo.7506305)
Dolmen OK1
strict Dolmen OK1
check-sat calls1
Query 1
Status unsat
Inferred Status unsat
Size 2391
Compressed Size913
Max. Term Depth4
Asserts 12
Declared Functions0
Declared Constants6
Declared Sorts 0
Defined Functions0
Defined Recursive Functions 0
Defined Sorts0
Constants0
Declared Datatypes0

Symbols

/16 +6 *14 >=12

Evaluations

Evaluation Rating Solver Variant Result Wallclock CPU Time
SMT-COMP 2024 0.40 (3/5) cvc5 cvc5 unsat ✅ 0.60177 0.50205
SMTInterpol SMTInterpol unknown ❌ 0.42370 0.44013
SMT-RAT SMT-RAT unsat ✅ 12.03530 11.93560
Yices2 Yices2 unknown ❌ 1201.21636 1200.57622
Z3alpha Z3-alpha unsat ✅ 0.32944 0.23000
SMT-COMP 2025 0.33 (4/6) cvc5 cvc5 unsat ✅ 0.61014 0.49295
SMTInterpol SMTInterpol unknown ❌ 0.46745 0.45284
SMT-RAT SMT-RAT unsat ✅ 0.89990 0.78346
Yices2 Yices2 unknown ❌ 1201.25956 1200.97438
Z3alpha Z3-alpha unsat ✅ 0.89337 1.71550
Z3 Z3-alpha-base unsat ✅ 0.56671 0.43695
z3siri-base unsat ✅ 0.45026 0.32838