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8 Development History
 8.1 Versions of the Package
 8.2 What needs to be done next?

8 Development History

8.1 Versions of the Package

The first version, GraphGpd 1.001, formed part of Emma Moore's thesis [Moo01] in December 2000, but was not made generally available.

Version 1.002 of GraphGpd was prepared to run under GAP 4.4 in January 2004; was submitted to the GAP council to be considered as an accepted package; but suggestions from the referee were not followed up.

In April 2006 the manual was converted to GAPDoc format. Variables Star, Costar and CoveringGroup were found to conflict with usage in other packages, and were renamed VertexStar, VertexCostar and CoveringGroupOfGroupoid respectively. Similarly, the Vertices and Arcs of an FpWeightedDigraph were changed from attributes to record components.

In the spring of 2006 the package was extensively rewritten and renamed gpd. Version 1.01 was submitted as a deposited package in June 2006. Version 1.03, of October 2007, fixed some file protections, and introduced the test file gpd_manual.tst.

Version 1.05, of November 2008, was released when the website at Bangor changed.

Since then, the package has been rewritten again, introducing magmas with objects and their mappings. Functions to implement constructions contained in [AW10] have been added, but this is ongoing work.

Versions 1.09 to 1.15 were prepared for the anticipated release of GAP 4.5 in June 2012.

gpd became an accepted GAP package in May 2015.

In April 2017 the package was renamed again, as groupoids.

The latest version is 1.51 of 6th August 2017, for GAP 4.8.8 or 4.9.

In the current version there have been a number of changes of function name, such as IsDigraph becoming GroupoidIsDigraph. This is in order to avoid conflicts with the Digraphs package. The intention is that these functions can revert to the original names in due course.

8.2 What needs to be done next?

The urgent requirement is for a new implementation of groupoid homomorphisms to eliminate the errors mention in section 5.4.

Computationally, there are three types of connected groupoid:

GraphGpd attempted to implement the second case, while gpd 1.01 and 1.03 considered only the first case, and gpd 1.05 extended 1.03 to the second case.

The third case has not yet been considered for implementation, and there does not appear to be any need to do so.

Here are some other immediate requirements:

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