How to solve: Error: the value of TRIPLE-STORE::UPI-1 is !ex:B, which is not of type UPI-LISP-TYPE

Hello,

I'm trying to use the SNA functionality of AllegroGraph.

According to the  documentation

http://agraph.franz.com/support/documentation/current/reference-guide.html#function.nodal-degree

I tried the following:

1- First I inserted 2 triples without problems:

(open-triple-store "/home/cas/Documents/source/Lisp/ilc/music")
(register-namespace "ex" "http://www.franz.com/things#" :errorp nil)

(add-triple !ex:A !ex:linksTo !ex:B)
(add-triple !ex:C !ex:linksTo !ex:B)

Then I evaluated the following, again without any problems:

(defsna-generator linksTo (node)  (:objects-of :p !ex:linksTo))
(defsna-generator linksFrom (node)  (:subjects-of :p !ex:linksTo))
(defsna-generator links (node)  (:undirected :p !ex:linksTo))

However when I tried:

(nodal-degree (resource "B" "ex") 'linksTo)

I received the error message:

Error: the value of TRIPLE-STORE::UPI-1 is !ex:B, which is not of type
UPI-LISP-TYPE.

I also tried:

(nodal-degree !ex:B 'linksTo)

Again:

Error: the value of TRIPLE-STORE::UPI-1 is !ex:B, which is not of type
UPI-LISP-TYPE.
[condition type: TYPE-ERROR]

I think I did exactly as shown in the documentation. Why do I get this error?
Any help will be appreciated.

I received that error using Allegro CL 8.1 Express Edition and AllegroGraph



-- 
Emre Sevinc

Lecturer @ Istanbul Bilgi University Computer Science Department
Coordinator @ IBM Center for Advanced Studies Lab.
http://cs.bilgi.edu.tr
http://cas.bilgi.edu.tr/cms/
http://cs.bilgi.edu.tr/~emres/