1. Lola
a low-level Petri net analyzer
sERvice-TeChNoLoGy.org
sERvice-techNoLoGy.org

2. Who is this “LoLA”?
• a low-level Petri net analyzer
• everything is based on Petri nets
• low level: N = [P, T, F, V, m0 ]
• an explicit state space verification tool
• a model checker
sERvice-TeChNoLoGy.org

3. .lola LL
.lola HL
.pnml
Petri net “Yes!”
model witness
path text
LoLA marking
state space
Question “No!”
specification counterexample
marking formula
predicate place sERvice-TeChNoLoGy.org

4. p1 1
3 x t
[x, y]
x>y p3
p2 2
1 y
p1.1 ld
n fo
u
p1.2
t.[x=3|y=1]
p1.3 p3.<3|1>
p2.1 p3.<3|2>
p2.2 t.[x=3|y=2]
p2.3 sERvice-TeChNoLoGy.org

5. LoLA is curious
• Petri nets • Temporal properties
• deadlock freedom • AGEF (liveness)
• boundedness • GF (fairness)
• liveness • FG (stabilization)
• reachability • F (eventually)
• home markings
• reversibility • Temporal logics
• quasi-liveness • CTL
sERvice-TeChNoLoGy.org

6. LoLA is lazy modest
• partial order reduction
• symmetry reduction smaller
• sweep line statespace
• cycle reduction
• invariant compression smaller markings
• structural reduction
sERvice-TeChNoLoGy.org

7. LoLA is focused
• Be as specific as possible!
• Rather check 1000 small state spaces than
one that is too big.
• Know your problem and the theory (sorry)!
• Performance, performance, performance.
• User-experience... But there is ProM...
sERvice-TeChNoLoGy.org

8. sERvice-TeChNoLoGy.org

9. LoLA is determined
• memoryless simulation influenced by
• partial order reduction (goal-oriented)
• path length (domain knowledge)
• randomness (don’t fool me twice...)
sERvice-TeChNoLoGy.org

10. sERvice-TeChNoLoGy.org

11. LoLA is versatile
asynchronous hardware circuits
IBM business processes
BPEL service choreographies
cellular biology reaction chains
AI planning
business rule compliance
sERvice-TeChNoLoGy.org

12. LoLA is sound
• Naive: AGEF final state
• Petri netty: short circuited net is live + bound
• LoLA:
1. check liveness of final marking
2. check boundedness for all places
(safety for free choice)
sERvice-TeChNoLoGy.org

13. LoLA is fast
• 33,000 - 100,000 states per second
• 42,000 - 120,000 transitions per second
• 450 - 800 MB per minute
• soundness: 4 ms per process
• bottleneck: memory allocation, I/O
sERvice-TeChNoLoGy.org

14. LoLA has many friends
• The Petri Net Kernel
• The Model Checking Kit
• CPN-AMI
• the sisters: Fiona, Wendy, Marlene, and Mia
• soon: ProM, Oryx
• you?
sERvice-TeChNoLoGy.org

15. Meet LoLA!
• http://service-technology.org/lola
• lola@service-technology.org
sERvice-TeChNoLoGy.org

16. Lola
a low-level Petri net analyzer
So on in
a ProM
you!
near
sERvice-TeChNoLoGy.org
sERvice-techNoLoGy.org