Installing the Pathway Logic Assistant (PLA)


The Pathway Logic Assistant (PLA) relies on several programs that must be installed to use it. Below are instructions for obtaining those programs that you don't already have. Followed by the very simple instructions for installing and running PLA. Hopefully you won't be discouraged. As PLA matures, installation will get simpler, and once you have all the auxilliaries, updates will be easy!

PLA requires Maude and the IOP Platform along with the dot graph layout utilities to be installed. Furthermore, you need to have Oracle's Java 1.6 aka 6.0.

We support Linux and Mac OS X platforms as the required programs run on these. If you are using a platform not supported, you can try out Online PLA with the sample models supplied on our site.


PLA requires Core Maude 2.2 or higher. You can can obtain the latest Core Maude from More documentation and details about Maude are available at

Set the MAUDE_LIB environment variable to include the directory where you put Maude and associated files. For example, if you chose to install Maude in "~/Maude/bin", then users running a csh or tcsh might add

  setenv MAUDE_LIB ${HOME}/Maude/bin
to their .cshrc file. Users running sh or bash would use
  export MAUDE_LIB=$HOME/Maude/bin
in their .profile or .bashrc file.

This installation come with a Maude executable for each supported platform (currently: maude.intelDarwin, maude.linux, and maude.linux64). PLA assumes that your Maude executable is called maude. You can either do this by renaming, or creating a soft link. Making a soft link is easy, for example on a Mac:
ln -s maude.intelDarwin maude

The IOP Platform

Download and install "iop"

Download and install iop iopc GitHub page.

Install "dot"

For IOP to support PLA you need to have the GraphViz program dot installed. See the GraphViz website for more details.

Pathway Logic Assistant

Now download PLA from the Download page, and follow the instructions in the README.txt file that sits in unzipped downloaded directory.