PERA: package for extended relation algebras

PERA is a set of files programmed in Maple allowing to use relation algebras extended with a neighborhood structure.
It allows to describe relational algebras, use them (through composition of inverse tests for instance) and manipulate them (through product, weakening or interval composition).

The relation algebra structure

PERA deals with (binary) relation algebras extended with a neighborhood structure.
For a very simple presentation (in french) look at [Euzenat 1998a]. For more information, one can consult the Maple worksheet which contains more references.

What can be done

A good example of what can be done with PERA is provided in the PERA worksheet. For those non familiar with Maple, the PostScript version of the worksheet is provided here.

To sum up, PERA allows to:

It does not implements constraint satisfaction algorithms for testing satisfiability or finding the minimal labels.

It does not either consider the inference of granularity conversion operators by any automatic mean (but maybe...).

Maple specifics

This is not a package in the MAPLE sense.

Where to download the package

Here you an get the set of files for the current version (1.0) in compressed format. It includes:
This file
the system
Algebra of relations for point algebras (with branching past and future);
Algebras of relations for interval algebra (Allen);
A worksheet displaying the features of the package;
The PostScript output of the former (which displays a bug in pointisable).