Algernon Tutorial 2.a
Continuing with queries

These exercises and examples use the newspaper project included in the examples folder of your Protege installation.

A more complicated query

• ((:instance Article ?article)
(headline ?article ?headline)
(article_author ?article ?auth)
(byname ?auth ?author))
  Run this query, printing the variables ?headline and ?author.
• It returns 5 headline/author pairs.
• However, there are 9 articles.
  You can retrieve 8 of them by removing the byname clause from the above path.
• Identify the branch point(s) in the above path.

Related links

• Algernon macros