The Causal Calculator

The Causal Calculator (CCalc) is a system for representing commonsense knowledge about action and change. It implements a fragment of the causal logic described in the paper "Nonmonotonic causal theories" by Enrico Giunchiglia, Joohyung Lee, Vladimir Lifschitz, Norman McCain and Hudson Turner (Artificial Intelligence, Vol. 153, 2004, pp. 49-104). The original version of CCalc was part of Norman McCain's dissertation, Causality in commonsense reasoning about actions (University of Texas, 1997). Now the system is being maintained by Texas Action Group at Austin.

The semantics of the language of CCalc is related to default logic and logic programming. Computationally, CCalc uses ideas of satisfiability planning.

CCalc at UT Austin

On the machines of the Department of Computer Sciences of the University of Texas at Austin, CCalc is installed in the /projects/tag/ccalc/ directory.

To execute Sicstus Prolog on a Sun machine, use the command

     % /projects/prolog/sicstus3.7.1/sparc5native/sicstus

For SWI Prolog (on GNU/Linux or Sun):

     % /lusr/opt/pl-5.6.50/bin/pl

How to Download CCalc

To run CCalc, you need to have either SICStus Prolog (version 3.7.1 or later) or SWI Prolog (version 5.6.49 or later).

Download the file

     ccalc-2.0r1.tar.gz

and unpack it using the commands

     % gunzip ccalc-2.0r1.tar.gz
     % tar -xvf ccalc-2.0r1.tar

CCalc 2.0 will be installed in directory ccalc created under your current directory.

Satisfiability solvers compiled for Linux and SunOS are provided with CCalc. If you will run CCalc under a different operating system, you may need to obtain or recompile the SAT solvers for your system. Please see the file README, in the ccalc directory after you unzip it, for instructions on how to do this.

On-line Tutorial

Examples of Action Domains Described in the Language of CCalc

If you liked CCalc then you may be also interested in systems

ASSAT, BLACKBOX, CMODELS, DLV, SMODELS and VITAL.

Questions? Send an e-mail to ccalc-help@cs.utexas.edu.