Running ProB from source

ProB Source Code

The kernel of ProB is written in Prolog and you can download the latest Prolog sourcecode snapshot from:

You may also wish to obtain related Java sources:

Running ProB from Prolog

You first need to download and install SICStus Prolog. Evaluation licenses (30-days) are available. We currently compile with SICStus 4.6.0 (as of January 2021).

You need the password to download SICStus then run sudo ./InstallSICStus and provide the site name, license code and expiration date. Be sure to add the SICStus binaries to your PATH.

Now, you need to clone or download the ProB Prolog sources.

Building ProB Extensions

Before using ProB for the first time from source you should build the extensions. The minimal extensions are counter and user_signal. You can build them using

cd extensions/counter
cd ../user_signal

You will also need the ProB parser, which can be downloaded or updated using the command

./gradlew updateParser

You could also build all extensions at once by going to the top of the prob_prolog tree (i.e., the directory containing src and lib as sub-directories) and then type


On Mac you may have to add a symbolic link to gawk in order to build the ProZ fuzz extension:

sudo ln -s /usr/bin/awk /usr/bin/gawk

An alternative is to download ProB from the Download download page, unzip the archive and copy all the files in the lib folder of the archive to the lib folder of your Prolog source code.

Starting ProB Tcl/Tk

Probably you should first install a recent Active Tcl distribution, in particular on macOS. Check the Download download page for which version is required or recommended.

You can then start ProB Tcl/Tk by changing into the prob_prolog directory of the Prolog sources and type:

sicstus -Dprob_profile=true -l src/ --goal "go."'

To simplify starting ProB, add the following to your .bash_login file (or similar configuration file; supposing you cloned the Git repository into ~/git_root):

export PROBDIR=~/git_root/prob_prolog
alias prob='cd sicstus -Dprob_profile=true -l $PROB_SOURCE_DIR/ --goal "go."'

Now, you can simply start ProB from the command-line and from source with the prob alias command.

Starting probcli command-line version

The command-line version of ProB does not require a Tcl/Tk distribution.

To start probcli from source define this alias, where PROB_SOURCE_DIR and SICSTUSDIR must be defined:

alias probsli='rlwrap $SICSTUSDIR/bin/sicstus -l $PROB_SOURCE_DIR/ --goal "go_cli." -a'

(It is recommended to install rlwrap so that you get a history of your commands. If you don't want to install rlwrap just remove it from the line above.)

You can now use probsli just like probcli, e.g.,

probsli M.mch --model-check


probsli --repl

Running the Prolog Tests

All Prolog tests are stored as facts in the file test Every test has

  • an identifier (a number); the last test added has the highest number
  • a non-empty list of categories (such as unit, tickets,...)
  • the test itself: the parameters to probcli needed to run the test
  • a textual description of the test

There is a specific file for running all Prolog unit and integration tests. The test_runner also provides a REPL (read-eval-print-loop) for running tests and collection of tests. To start the Unit Test REPL, add the following to your .bash_login file (at least on Mac OS):

alias tests='cd $PROBDIR; rlwrap sicstus -Dprob_safe_mode=true -l $PROB_SOURCE_DIR/ --goal "test_repl."'

(It is recommended to install rlwrap so that you get a history of your commands. If you don't want to install rlwrap just remove it from the line above.)

Now you can start the test runner like this:


or you can already specify tests to be run:

tests last

You can also type the number of a unit test to run, or a test category such as tickets to run all tests in that category.

Here is a sample sesssion of running the test REPL:

$ tests
SICStus 4.2.3 (x86_64-darwin-11.4.2): Fri Oct  5 15:58:35 CEST 2012
Licensed to
TEST ==> last.
All tests successful.
Walltime: 100 ms

Some useful commands in the REPL are:

  • last to run the last test added to
  • all to run all tests
  • cat to list all categories of tests (e.g., cbc, cbc_deadlock,...)
  • cbc, cbc_deadlock, tickets, ... : to run all tests in that category
  • type in a number to run the specific test with that number (see
  • type in a range m-n to run all tests in that range
  • v or vv to switch to verbose or very verbose mode
  • q to quit the test runner (and stay in Prolog)
  • x to quit the test runner and Prolog
  • debug to switch on Prolog debug mode
  • trace to force Prolog to start tracing as soon as an error occurs (if you have switched to debug above then you will be able to inspect the Prolog goal stack)

ProB Prolog compile time flags

By giving sicstus a command-line option -Dflag=true you can set certain compile time flags, namely:

prob_profile (enables B operation profiling to be displayed in ProB Tcl/Tk in Debug menu)
prob_safe_mode (performs additional checking, in particular that ASTs are well-formed)
prob_data_validation_mode  (deprecated, replaced by DATA_VALIDATION preference)
prob_release (removes certain tests from the code)
no_terminal_colors (disable terminal colors)
debug_kodkod (write dot files for kodkod interval analysis)
no_wd_checking (disable WD checking for function application)