pbessolvesymbolic
This is a solving tool for parameterised Boolean equation systems (.pbes extension) that is based on a parity game exploration technique that utilises symbolic representations. The symbolic exploration works very similar to the one implemented by lpsreach, where it is described in great detail. The main difference is that the underlying PBES is first transformed into a standard recursive format (SRF), which is in some sense very similar to a linear process.
Next, we describe useful options that are exclusive to pbessolvesymbolic. One option that can be useful to further refine the dependencies of transition groups is –split-conditions, which introduces new transition groups based on the structure of the SRF pbes. Generally, option 1 is safe, but options 2 and 3 can yield an infinite PBES due to the conditions becoming weaker.
Similarly to pbessolve the pbessolvesymbolic tool also contains various partial solving strategies that attempt to optimistically solve the intermediate parity games to present the solution (and terminate) early. These can be enabled with the –solve-strategy option.
Limitations
Currently, pbessolvesymbolic can not provide counter examples when the property does not hold, and solving PBESs with counter example information is extremely slow.
- orphan:
Usage
pbessolvesymbolic [OPTION]... [INFILE [OUTFILE]]
Description
Solves PBES from INFILE. If INFILE is not present, stdin is used. The PBES is first instantiated into a parity game, which is then solved using Zielonka’s algorithm.
Command line options
--cached
use transition group caching to speed up state space exploration
--chaining
reduce the amount of breadth-first iterations by applying the transition groups consecutively
--groups[=GROUPS]
‘none’ (default) no summand groups
‘used’ summands with the same variables are joined ‘simple’ summands with the same read/write variables are joined a user defined list of summand groups separated by semicolons, e.g. ‘0; 1 3 4; 2 5’
--info
print read/write information of the summands
--lace-dqsize[=NUM]
set length of Lace task queue (default 1024*1024*4)
--lace-stacksize[=NUM]
set size of program stack in kilobytes (0=default stack size)
--max-iterations[=NUM]
limit number of breadth-first iterations to NUM
-m[NUM] , --memory-limit[=NUM]
Sylvan memory limit in gigabytes (default 3)
--print-exact
prints the sizes of LDDs exactly when within the representable range, and in scientific notation otherwise
--print-nodesize
print the number of LDD nodes in addition to the number of elements represented as ‘elements[nodes]’
-QNUM , --qlimit=NUM
limit enumeration of quantifiers to NUM iterations. (Default NUM=1000, NUM=0 for unlimited).
--reorder[=ORDER]
‘none’ (default) no variable reordering
‘random’ variables are put in a random order ‘a user defined permutation e.g. ‘1 3 2 0 4’
--reset
set constant values when introducing parameters
-rNAME , --rewriter=NAME
use rewrite strategy NAME:
jittyjitty rewriting
jittyccompiled jitty rewriting
jittypjitty rewriting with prover
--saturation
reduce the amount of breadth-first iterations by applying the transition groups until fixed point
-sNUM , --solve-strategy=NUM
Use solve strategy NUM. All strategies except 0 periodically apply on-the-fly solving, which may lead to early termination.
0No on-the-fly solving is applied
1Detect solitair winning cycles.
2Detect solitair winning cycles with safe attractors.
3Detect forced winning cycles.
4Detect forced winning cycles with safe attractors.
5Detect fatal attractors.
6Detect fatal attractors with safe attractors.
7Solve subgames using a Zielonka solver.
-c[NUM] , --split-conditions[=NUM]
split conditions to obtain possibly smaller transition groups
0 (default) no splitting performed. 1 only split disjunctive conditions. 2 also split conjunctive conditions into multiple equations which often yield more reachable states. 3 alternative split for conjunctive conditions where even more states can become reachable.
--threads=NUM
run with NUM threads (default=1). With multiple threads the stack size on a Mac is limited which can lead to bus errors.
--timings[=FILE]
append timing measurements to FILE. Measurements are written to standard error if no FILE is provided
-t , --total
make the SRF PBES total
Standard options
-q , --quiet
do not display warning messages
-v , --verbose
display short intermediate messages
-d , --debug
display detailed intermediate messages
--log-level=LEVEL
display intermediate messages up to and including level
-h , --help
display help information
--version
display version information
--help-all
display help information, including hidden and experimental options