Algernon Tutorial 1.g
Simple Queries

Simple queries

• ((:DIRECT-SUBCLASS Author ?x))      Returns 4 bindings for ?x
  Note: :DIRECT-SUBCLASS is an Algernon macro, not the similarly-named Protege slot.
• Clear the variable list first, then Ask:
  ((:DIRECT-SUBCLASS Author ?x)(:INSTANCE ?x ?y))      Returns 9 binding lists.
• Clear the variable list, then Ask:
  ((:DIRECT-SUBCLASS Author ?x)(:INSTANCE ?x ?y)(name ?y ?name))      Returns only 7 binding lists. Why?
• Clear the variable list, then Ask:
  ((:INSTANCE :THING ?x))      Returns 181 bindings for ?x
• Look at the newspaper class hierarchy and make up your own query using :DIRECT-SUBCLASS, :DIRECT-SUPERCLASS, :INSTANCE and the slots of the different frames.
• Bonus question: Which design decisions in the Newspaper ontology complicate the task of writing general queries against this KB?

Related links

• Algernon macros