| [from Bryan Pogson, AICU, Basingstoke U.K.
Bryan is at SPYDER::POGSON or POGSON@USH]
Dear all,
I have just recieved the latest version of Egeria, v1.1. This appears to be
a version with fewer bugs than 1.0 but not much change in functionality.
The new version comes with 2 books carved out of solid marble. As well as the
manual which is written in TechnoGibberish and is best understood after you've
spent 2 years programming the thing, there is a 435-page tutorial called
"Expert Systems with Egeria" which looks more suitable for bedtime reading.
(Unless you can think of better things to do at bedtime.)
My first impressions of Egeria are:
- *very* powerful language for probably all types of ES
- frames, inheritance, object sets created on the fly
- one:many, one:one, many:many relationships on the fly
- very good pattern matching through inheritance, relationships
or simple variables; set operations
- very good control: demons, internal procedural language
tasks, user-defined functions
- good modularity within a knowledge base (scoping local to
classes of objects also covers local procedures, tasks and
display windows
- ISI claim their implementation of Bayes' is the only correct
one... haven't checked this
- strongly typed including enumerated variables
- can do simple list operations but not Lisp-like
- can do a sort of predicate logic through relationships but
it's not Prolog
- its a language: no syntax-directed editor, or debugger
(there is a run-time browser)
- no incremental compilation, but no need to VMS-link unless using
external functions
- moderate integration with VMS (it's really a PC product)
- can call external functions and could (I think) be called
- output window editor knows nothing about DECWindows, UIS etc
but runtime i/o system could be modified by 'C' programming
- will take a longish time to learn
- likely to be a bit buggy (Savoir was for its first few months)
- support good from ISI
but I'll report some more when I've got more experience of it (probably in a
few months time).
I'll be happy to discuss it with anyone.
Regards,
Bryan
|
| The latest on Egeria is not good: it's dead. ISI was taken over by
Expertech in 1989. They could not then fully support it since only 2 or
3 of the original developers stayed with the new company. Very few
Egerias, if any, were sold.
Expertech have now been taken over by Inference Corp to form Inference
(Europe) which continue to market Expetech's Xi Plus along with ART and
ART im. They have dropped Egeria from their price list. It is not
clear why: I guess it may be because of overlap with ART which could have
damaged its sales.
Egeria was potentially a good product: to be an excellent product on
our kit it needs DECwindows development and user environments and
better tailored access to the OS: the underlying knowledge
representation and inferencing is good. Maybe Inference (if they have
the rights) would sell it to anyone who wanted to develop it further.
|