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The installation of the major Potassco tools is rather straightforward.
We suggest to start with downloading the most recent version of the ASP system clingo
For experiencing ASP with clingo
, we recommend to begin with the
It contains a light introduction to the input language of clingo
provides easy modeling examples, and discusses its usage.
To get a quick first impression, you may want to experiment with running clingo
in your browser.
In ASP, a problem is described by a set of rules.
For example, the rule
innocent(Suspect) :- motive(Suspect), not guilty(Suspect).
expresses that a Suspect
is considered innocent if
she has a motive and
she was not found guilty
The symbols `:-
' and `,
' stand for if
The symbol `not
' stands for (default) negation.
, and motive
are user-defined predicates,
provides a user-defined variable that can be replaced by specific terms (representing objects).
Variables start with uppercase letters, predicates and terms (usually) begin with lowercase letters.
Finally, each rule must be terminated with a period `.
' to signal the end of the rule.
Facts are rules without any conditions.
This is why the if
' is omitted.
Example facts are
Solutions to a problem, or simply answer sets, are given by sets of atomic propositions
that are supposed to be true in the answer set; false propositions are omitted.
A solution to the above rule and the three facts is the answer set containing
all three facts as well as the proposition innocent(sally)
This is because our rule applies to sally
but not harry
Let us reproduce this result with clingo
To begin with, we put the above rule along with the three facts in a file called crime.lp
The extension lp
is not necessary but helps to identify the type of file.
The ASP system clingo
allows us to compute the aforementioned answer set:
$ clingo files/crime.lp
clingo version 4.5.0
Reading from files/crime.lp
motive(harry) motive(sally) guilty(harry) innocent(sally)
A formal introduction to (a large fragment of) the input language of clingo
and its precise semantics can be found here
You may also be interested in the ASP-Core-2
language standard, a subset of the language of clingo
The foundations and algorithms underlying the grounding and solving technology used in clingo
as well as various modeling techniques are
described in detail in the Potassco book
Teaching material and links to further tutorials can be found in the teaching
similarly the video
section may find your interest.
An overview of our major tools is given on the main Potassco page
Corresponding executables for Linux, MacOS, and Windows as well as source packages are available on
the download page
Still experimental software is found in the Potassco labs
section, and may need more care during installation.
If you have a question, it's a good idea to try at first the FAQ
, which answers the most commonly asked questions about our tools.
Your next best bet is to check the archive of the potassco-users
If you need further help, feel free to post your question to the potassco-users
Bug reports and feature requests can be posted to the
For gossip and release announcements you may want to join our Google+ group