Skip to main content

The first reactive synthesis competition (SYNTCOMP 2014)


We introduce the reactive synthesis competition (SYNTCOMP), a long-term effort intended to stimulate and guide advances in the design and application of synthesis procedures for reactive systems. The first iteration of SYNTCOMP is based on the controller synthesis problem for finite-state systems and safety specifications. We provide an overview of this problem and existing approaches to solve it, and report on the design and results of the first SYNTCOMP. This includes the definition of the benchmark format, the collection of benchmarks, the rules of the competition, and the five synthesis tools that participated. We present and analyze the results of the competition and draw conclusions on the state of the art. Finally, we give an outlook on future directions of SYNTCOMP.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6


  1. See also: the Hardware Model Checking Competition, Accessed February 2016.

  2. For simplicity, we assume that is a latch. If is not a latch in the given monitor circuit, then it can be described as a formula \(f(L,X_u,X_c)\). In this case we can obtain a problem in the described form by extending the circuit with a new latch that takes \(f(L,X_u,X_c)\) as an input and provides output .

  3. Accessed February 2016.

  4. Accessed February 2016.

  5. Accessed February 2016.

  6. The reason for disallowing original AND-gates is that we want the controller to work only based on the state of the given circuit (i.e., values of latches), and the uncontrollable inputs. Original AND-gates can be duplicated in the controller if necessary.

  7. Numbers regarding realizability are to the best of our knowledge. The realizability status has not been verified for all benchmark instances.

  8. Accessed February 2016.

  9. Accessed February 2016.

  10. Accessed February 2016.

  11. Accessed February 2016.

  12. Accessed February 2016.

  13. Accessed February 2016.

  14. Accessed February 2016.

  15. Accessed February 2016.

  16. We conjecture that this version is more challenging because it is based on a large LTL specification, which is translated to a single, very big Büchi automaton in the first step of the ltl2aig routine. This results in a circuit that is much more complex than the ones from Sect. 4.3.

  17. Accessed February 2016.

  18. In particular, non-trivial parallelization is difficult for BDD-based tools, since none of the existing parallel BDD packages supports all features needed for the optimizations mentioned in Sect. 2.3.

  19. The quality ranking was devised for the second SYNTCOMP and was applied to the results of the first competition only after the presentation of results at SYNT and CAV 2014.

  20. This rule only had to be used in one instance, where a benchmark was solved by only one tool, and was reported to be realizable although unrealizable was the expected outcome. In our analysis it turned out that the tool was correct, and the initial classification as unrealizable was wrong.

  21. Accessed February 2016.

  22. Accessed February 2016.

  23. Accessed February 2016.

  24. Accessed February 2016.

  25. Analysis of results and subsequent inspection of the source code by the tool author showed that due to a bug the parallel version did not work as intended, and instead used two threads with identical strategy. As can be seen in the results section, this lead to a decreased performance overall.

  26. Accessed February 2016.

  27. Accessed February 2016.

  28. Accessed February 2016.

  29. As mentioned in Sect. 6.1, AbsSynthe was supposed to compete in different configurations, but due to a miscommunication was always started in the same configuration. The results presented here for the relative ranking differ from those presented at CAV 2014 in that only one of the three identical configurations of AbsSynthe is counted in the sequential tracks.

  30. This benchmark was found to be realizable by the tool, although it was classified as unrealizable by the benchmark authors. Our analysis confirmed it to be realizable.

  31. Due to a bug, the parallel version of Realizer performed worse than the sequential version, as mentioned in Sect. 6.


  1. Alur, R., Bodík, R., Dallal, E., Fisman, D., Garg, P., Juniwal, G., Kress-Gazit, H., Madhusudan, P., Martin, M.M.K., Raghothaman, M., Saha, S., Seshia, S.A., Singh, R., Solar-Lezama, A., Torlak, E., Udupa, A.: Syntax-guided synthesis. In: Dependable Software Systems Engineering, NATO Science for Peace and Security Series, D: Information and Communication Security, vol. 40, pp. 1–25. IOS Press (2015)

  2. Alur, R., Madhusudan, P., Nam, W.: Symbolic computational techniques for solving games. STTT 7(2), 118–128 (2005)

    Article  MATH  Google Scholar 

  3. Aziz, A., Tasiran, S., Brayton, R.K.: BDD variable ordering for interacting finite state machines. In: DAC, pp. 283–288 (1994)

  4. Balint, A., Diepold, D., Gall, D., Gerber, S., Kapler, G., Retz, R.: EDACC - an advanced platform for the experiment design, administration and analysis of empirical algorithms. In: LION 5. Selected Papers, LNCS, vol. 6683, pp. 586–599. Springer, (2011)

  5. Barrett, C.W., de Moura, L.M., Stump, A.: Design and results of the first satisfiability modulo theories competition (SMT-COMP 2005). J. Autom. Reason. 35(4), 373–390 (2005)

    Article  MATH  Google Scholar 

  6. Beyer, D.: Competition on software verification - (SV-COMP). In: TACAS, LNCS, vol. 7214, pp. 504–524. Springer (2012)

  7. Beyer, D., Löwe, S., Wendler, P.: Benchmarking and resource measurement. In: SPIN 2015, LNCS, vol. 9232, pp. 160–178. Springer (2015)

  8. Bloem, R., Cimatti, A., Greimel, K., Hofferek, G., Könighofer, R., Roveri, M., Schuppan, V., Seeber, R.: RATSY - A new requirements analysis tool with synthesis. In: CAV, LNCS, vol. 6174, pp. 425–429. Springer (2010)

  9. Bloem, R., Egly, U., Klampfl, P., Könighofer, R., Lonsing, F.: SAT-based methods for circuit synthesis. In: FMCAD’14, pp. 31–34. IEEE (2014)

  10. Bloem, R., Galler, S.J., Jobstmann, B., Piterman, N., Pnueli, A., Weiglhofer, M.: Automatic hardware synthesis from specifications: a case study. In: DATE, pp. 1188–1193. ACM (2007)

  11. Bloem, R., Galler, S.J., Jobstmann, B., Piterman, N., Pnueli, A., Weiglhofer, M.: Specify, compile, run: hardware from PSL. Electr. Notes Theor. Comput. Sci. 190(4), 3–16 (2007)

    Article  Google Scholar 

  12. Bloem, R., Jobstmann, B., Piterman, N., Pnueli, A., Sa’ar, Y.: Synthesis of reactive(1) designs. J. Comput. Syst. Sci. 78(3), 911–938 (2012)

    Article  MathSciNet  MATH  Google Scholar 

  13. Bloem, R., Könighofer, R., Seidl, M.: SAT-based synthesis methods for safety specs. In: VMCAI, LNCS, vol. 8318, pp. 1–20. Springer (2014)

  14. Bohy, A., Bruyère, V., Filiot, E., Jin, N., Raskin, J.-F.: Acacia+, a tool for LTL synthesis. In: CAV, LNCS, vol. 7358, pp. 652–657. Springer (2012)

  15. Bradley, A.R.: SAT-based model checking without unrolling. In: VMCAI, LNCS, vol. 6538, pp. 70–87. Springer (2011)

  16. Brayton, R.K., Hachtel, G.D., Sangiovanni-Vincentelli, A.L., Somenzi, F., Aziz, A., Cheng, S., Edwards, S.A., Khatri, S.P., Kukimoto, Y., Pardo, A., Qadeer, S., Ranjan, R.K., Sarwary, S., Shiple, T.R., Swamy, G., Villa, T.: VIS: a system for verification and synthesis. In: CAV, LNCS, vol. 1102, pp. 428–432. Springer (1996)

  17. Brayton, R.K., Mishchenko, A.: ABC: an academic industrial-strength verification tool. In: CAV, LNCS, vol. 6174, pp. 24–40. Springer (2010)

  18. Brenguier, R., Pérez, G.A., Raskin, J.-F., Sankur, O.: AbsSynthe: abstract synthesis from succinct safety specifications. In: SYNT, EPTCS, vol. 157, pp. 100–116. Open Publishing Association (2014)

  19. Bryant, R.E.: Graph-based algorithms for boolean function manipulation. IEEE Trans. Comput. 35(8), 677–691 (1986)

    Article  MATH  Google Scholar 

  20. Büchi, J., Landweber, L.: Solving sequential conditions by finite-state strategies. Trans. Am. Math. Soc. 138, 295–311 (1969)

    Article  MATH  Google Scholar 

  21. Burch, J.R., Clarke, E.M., Long, D.E.: Symbolic model checking with partitioned transistion relations. In: VLSI, pp. 49–58 (1991)

  22. Chiang, T., Jiang. J.R.: Property-directed synthesis of reactive systems from safety specifications. In: ICCAD, pp. 794–801. ACM (2015)

  23. Church, A.: Logic, arithmetic and automata. In: Proceedings of the International Congress of Mathematicians, pp. 23–35 (1962)

  24. Coudert, O., Madre, J.C.: A unified framework for the formal verification of sequential circuits. In: ICCAD, pp. 126–129 (1990)

  25. Cousot, P., Cousot, R.: Abstract interpretation: A unified lattice model for static analysis of programs by construction or approximation of fixpoints. In: POPL, pp. 238–252. ACM (1977)

  26. de Alfaro, L., Roy, P.: Solving games via three-valued abstraction refinement. In: CONCUR, LNCS, vol. 4703, pp. 74–89. Springer (2007)

  27. Ehlers, R.: Experimental aspects of synthesis. In: iWIGP, EPTCS, vol. 50, pp. 1–16 (2011)

  28. Ehlers, R.: Unbeast: symbolic bounded synthesis. In: TACAS, LNCS, vol. 6605, pp. 272–275. Springer (2011)

  29. Ehlers, R.: Symbolic bounded synthesis. Formal Methods Syst. Des. 40(2), 232–262 (2012)

    Article  MATH  Google Scholar 

  30. Ehlers, R., Könighofer, R., Hofferek, G.: Symbolically synthesizing small circuits. In: FMCAD’12, pp. 91–100. IEEE (2012)

  31. Emerson, E.A., Clarke, E.M.: Using branching time temporal logic to synthesize synchronization skeletons. Sci. Comput. Program. 2(3), 241–266 (1982)

    Article  MATH  Google Scholar 

  32. Filiot, E., Jin, N., Raskin, J.: Exploiting structure in LTL synthesis. STTT 15(5–6), 541–561 (2013)

    Article  Google Scholar 

  33. Filiot, E., Jin, N., Raskin, J.-F.: Antichains and compositional algorithms for LTL synthesis. Formal Methods Syst. Des. 39(3), 261–296 (2011)

    Article  MATH  Google Scholar 

  34. Finkbeiner, B., Jacobs, S.: Lazy synthesis. In: VMCAI, LNCS, vol. 7148, pp. 219–234. Springer (2012)

  35. Finkbeiner, B., Schewe, S.: Bounded synthesis. STTT 15(5–6), 519–539 (2013)

    Article  MATH  Google Scholar 

  36. Graf, S., Saïdi, H.: Construction of abstract state graphs with PVS. In: CAV, LNCS, vol. 1254, pp. 72–83. Springer (1997)

  37. Henzinger, T.A., Jhala, R., Majumdar, R.: Counterexample-guided control. In: ICALP, LNCS, vol. 2719, pp. 886–902, Springer (2003)

  38. Hong, Y., Beerel, P.A., Burch, J.R., McMillan, K.L.: Sibling-substitution-based BDD minimization using don’t cares. IEEE Trans. CAD of Integr. Circuits Syst. 19(1), 44–55 (2000)

    Article  Google Scholar 

  39. Jacobs, S.: Extended AIGER format for synthesis. CoRR (2014). arXiv:1405.5793. Accessed Feb 2016

  40. Jacobs, S., Bloem, R., Brenguier, R., Ehlers, R., Hell, T., Könighofer, R., Pérez, G.A., Raskin, J., Ryzhyk, L., Sankur, O., Seidl, M., Tentrup, L., Walker, A.: The first reactive synthesis competition (SYNTCOMP 2014). CoRR (2015). arXiv:1506.08726. Accessed Feb 2016

  41. Jacobs, S., Bloem, R., Brenguier, R., Könighofer, R., Pérez, G.A., Raskin, J.-F., Ryzhyk, L., Sankur, O., Seidl, M., Tentrup, L., Walker, A.: The second reactive synthesis competition (SYNTCOMP 2015). In: SYNT, EPTCS, vol. 202, pp. 27–57. Open Publishing Association (2016)

  42. Jacobs, S., Klein, F.: A high-level LTL synthesis format: TLSF v1.0. CoRR (2016). arXiv:1601.05228. Accessed Feb 2016

  43. Järvisalo, M., Berre, D.L., Roussel, O., Simon, L.: The international SAT solver competitions. AI Mag 33(1), 89–94 (2012)

    Google Scholar 

  44. Jobstmann, B., Bloem, R.: Optimizations for LTL synthesis. In: FMCAD, pp. 117–124. IEEE Computer Society (2006)

  45. Jobstmann, B., Galler, S.J., Weiglhofer, M., Bloem, R.: Anzu: A tool for property synthesis. In: CAV, LNCS, vol. 4590, pp. 258–262. Springer (2006)

  46. Kupferman, O., Vardi, M.Y.: Safraless decision procedures. In: FOCS, pp. 531–542. IEEE Computer Society (2005)

  47. Kurshan, R.P.: Automata-theoretic verification of coordinating processes. In: Analysis and Optimization of Systems: Discrete Event Systems, pp. 16–28. Springer (1994)

  48. Lecoutre, C., Roussel, O., van Dongen, M.R.C.: Promoting robust black-box solvers through competitions. Constraints 15(3), 317–326 (2010)

    Article  MATH  Google Scholar 

  49. Mishchenko, A., Chatterjee, S., Brayton, R.K.: Dag-aware AIG rewriting a fresh look at combinational logic synthesis. In: DAC, pp. 532–535. ACM (2006)

  50. Mishchenko, A., Chatterjee, S., Jiang, R., Brayton, R.: FRAIGs: A unifying representation for logic synthesis and verification. Technical report, EECS Department, U. C. Berkeley (2005)

  51. Morgenstern, A., Gesell, M., Schneider, K.: Solving games using incremental induction. In: IFM’13, LNCS 7940, pp. 177–191. Springer (2013)

  52. Niemetz, A., Preiner, M., Lonsing, F., Seidl, M., Biere, A.: Resolution-based certificate extraction for QBF. In: SAT’12, LNCS 7317, pp. 430–435. Springer (2012)

  53. Pnueli, A., Rosner, R.: On the synthesis of a reactive module. In: POPL, pp. 179–190. ACM Press (1989)

  54. Rabin, M.O.: Decidability of second-order theories and automata on infinite trees. Trans. Am. Math. Soc. 141, 1–35 (1969)

    MATH  Google Scholar 

  55. Ranjan, R.K., Aziz, A., Brayton, R.K., Plessier, B., Pixley, C.: Efficient bdd algorithms for fsm synthesis and verification. In: International Workshop on Logic Synthesis (1995)

  56. Roussel, O.: Controlling a solver execution with the runsolver tool. JSAT 7(4), 139–144 (2011)

    MathSciNet  MATH  Google Scholar 

  57. Rudell, R.: Dynamic variable ordering for ordered binary decision diagrams. In: ICCAD, pp. 42–47. IEEE Computer Society (1993)

  58. Seidl, M., Könighofer, R.: Partial witnesses from preprocessed quantified boolean formulas. In: DATE’14, pp. 1–6. IEEE (2014)

  59. Sohail, S., Somenzi, F.: Safety first: a two-stage algorithm for the synthesis of reactive systems. STTT 15(5–6), 433–454 (2013)

    Article  Google Scholar 

  60. Somenzi, F.: Binary decision diagrams. In: Calculational System Design, vol. 173, pp. 303. IOS Press (1999)

  61. Sutcliffe, G., Suttner, C.B.: Evaluating general purpose automated theorem proving systems. Artif. Intell. 131(1–2), 39–54 (2001)

    Article  MathSciNet  MATH  Google Scholar 

  62. Sutcliffe, G., Suttner, C.B.: The state of CASC. AI Commun. 19(1), 35–48 (2006)

    MathSciNet  MATH  Google Scholar 

  63. Thomas, W.: On the synthesis of strategies in infinite games. In: STACS, pp. 1–13 (1995)

  64. van Dijk, T., Laarman, A., van de Pol, J.: Multi-core BDD operations for symbolic reachability. Electron. Notes Theor. Comput. Sci. 296, 127–143 (2013)

    Article  Google Scholar 

  65. van Dijk, T., van de Pol, J.: Sylvan: Multi-core decision diagrams. In: TACAS 2015, LNCS, vol. 9035, pp. 677–691 Springer (2015)

Download references


We thank the anonymous reviewers for their detailed and insightful comments on drafts of this article. We thank Armin Biere for his advice on running a competition, and Ayrat Khalimov for supplying the reference implementation Aisy for the competition. The organization of SYNTCOMP 2014 was supported by the Austrian Science Fund (FWF) through projects RiSE (S11406-N23) and QUAINT (I774-N23), by the German Research Foundation (DFG) as part of the Transregional Collaborative Research Center “Automatic Verification and Analysis of Complex Systems” (SFB/TR 14 AVACS) and through project “Automatic Synthesis of Distributed and Parameterized Systems” (JA 2357/2-1), as well as by the Institutional Strategy of the University of Bremen, funded by the German Excellence Initiative. The development of AbsSynthe was supported by an F.R.S.-FNRS fellowship, and the ERC inVEST (279499) project. The development of Basil was supported by the Institutional Strategy of the University of Bremen, funded by the German Excellence Initiative. The development of \(\texttt {Demiurge}\) was supported by the FWF through projects RiSE (S11406-N23, S11408-N23) and QUAINT (I774-N23). The development of Realizer was supported by the DFG as part of SFB/TR 14 AVACS. The development of Simple BDD Solver was supported by a gift from the Intel Corporation, and NICTA is funded by the Australian Government through the Department of Communications and the Australian Research Council through the ICT Centre of Excellence Program.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Swen Jacobs.

Rights and permissions

Reprints and Permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Jacobs, S., Bloem, R., Brenguier, R. et al. The first reactive synthesis competition (SYNTCOMP 2014). Int J Softw Tools Technol Transfer 19, 367–390 (2017).

Download citation

  • Published:

  • Issue Date:

  • DOI: