Skip to main content

A simple Python model checking package

Project description

pyModelChecking

pyModelChecking is a small Python model checking package. Currently, it is able to represent Kripke structures, CTL, LTL, and CTL* formulas and it provides model checking methods for LTL, CTL, and CTL*. In future, it will hopefully support symbolic model checking.

Documentation

Here you can find the pyModelChecking documenation. It contains:

  • a brief introduction to Kripke structures, temporal logics and model checking
  • the user manual and some examples
  • the API manual

Examples

First of all, import all the functions and all the classes in the package.

>>> from pyModelChecking import *

In order to represent a Kripke structure use the Kripke class.

>>> K=Kripke(R=[(0,0),(0,1),(1,2),(2,2),(3,3)],
...          L={0: set(['p']), 1:set(['p','q']),3:set(['p'])})

CTL can be represented by importing the CTL module.

>>> from pyModelChecking.CTL import *

>>> phi=AU(True,Or('q',Not(EX('p'))))

>>> print(phi)

A(True U (q or not (EX p)))

Whenever a non-CTL formula is built, an exception is thrown.

>>> psi=A(F(G('p')))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "pyModelChecking/CTL/language.py", line 42, in __init__
    self.wrap_subformulas(phi,StateFormula)
  File "pyModelChecking/CTLS/language.py", line 59, in wrap_subformulas
    phi.__desc__,phi))
TypeError: expected a CTL state formula, got the CTL path formula G p

It is also possible to parse a string representing a CTL formula by using the Parser class in the module CTL.

>>> parser = Parser()

>>> psi = parser("A(true U (q or not E X p))")

>>> print(psi)

A(True U (q or not EX p))

>>> print(psi.__class__)

<class 'pyModelChecking.CTL.language.A'>

The function modelcheck in the module CTL finds the states of Kripke structure that model a given CTL formula.

>>>  modelcheck(K,phi)

set([1, 2])

The formula AFG p, which we tried to build above, is a LTL formula. The LTL module can be used to represent and model check it on any Kripke structure.

>>> from pyModelChecking.LTL import *

>>> psi=A(F(G('p')))

>>> print(psi)

A(G(F(p))

>>> modelcheck(K,psi)

set([3])

Strings representing formulas in the opportune language can be used as a parameter of the model checking function too.

>>> modelcheck(K,'A G F p')

set([3])

The module CTLS is meant to deal with CTL* formulas. It can also combine and model checks CTL and LTL formulas.

>>> from pyModelChecking.CTLS import *

>>> eta=A(F(E(U(True,Imply('p',Not('q'))))))

>>> print(eta,eta.__class__)

(A(F(E((True U (p --> not q))))), <class 'pyModelChecking.CTLS.language.A'>)

>>> rho=A(G(And(X('p'),'p')))

>>> print(rho,rho.__class__)

(A(G((X(p) and p))), <class 'pyModelChecking.CTLS.language.A'>)

>>> gamma=And(phi, psi)

>>> print(gamma,gamma.__class__)

(A(True U (q or not (EX p))) and A(G(F(p)))), <class 'pyModelChecking.CTLS.language.And'>)

>>> modelcheck(K,eta)

set([0, 1, 2, 3])

>>> modelcheck(K, psi)

set([3])

>>> modelcheck(K, gamma)

set([])

Whenever a CTL* formula is a CTL formula (LTL formula), CTL (LTL) model checking can be applied to it.

>>> import pyModelChecking.CTL as CTL

>>> CTL.modelcheck(K,eta)

set([0, 1, 2, 3])

>>> CTL.modelcheck(K,rho)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "pyModelChecking/CTL/model_checking.py", line 183, in modelcheck
    raise RuntimeError('%s is not a CTL formula' % (formula))
RuntimeError: A(G((X(p) and p))) is not a CTL formula

>>> import pyModelChecking.LTL as LTL

>>> LTL.modelcheck(K,rho)

set([3])

Copyright and license

pyModelChecking Copyright (C) 2015-2019 Alberto Casagrande acasagrande@units.it

pyModelChecking is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Files for pyModelChecking, version 1.3.1
Filename, size File type Python version Upload date Hashes
Filename, size pyModelChecking-1.3.1-py3-none-any.whl (47.2 kB) File type Wheel Python version py3 Upload date Hashes View hashes
Filename, size pyModelChecking-1.3.1.tar.gz (30.9 kB) File type Source Python version None Upload date Hashes View hashes

Supported by

Elastic Elastic Search Pingdom Pingdom Monitoring Google Google BigQuery Sentry Sentry Error logging AWS AWS Cloud computing DataDog DataDog Monitoring Fastly Fastly CDN DigiCert DigiCert EV certificate StatusPage StatusPage Status page