Editing Commonsense reasoning (section)

=== Taxonomic reasoning ===
Taxonomy is the collection of individuals and categories and their relations. Three basic relations are:
* An individual is an instance of a category. For example, the individual ''Tweety'' is an instance of the category ''robin''.
* One category is a subset of another. For instance ''robin'' is a subset of ''bird''.
* Two categories are disjoint. For instance ''robin'' is disjoint from ''penguin''.
Transitivity is one type of inference in taxonomy. Since ''Tweety'' is an instance of ''robin'' and ''robin'' is a subset of ''bird'', it follows that ''Tweety'' is an instance of ''bird''. Inheritance is another type of inference. Since ''Tweety'' is an instance of ''robin'', which is a subset of ''bird'' and ''bird'' is marked with property ''canfly'', it follows that ''Tweety'' and ''robin'' have property ''canfly''.

When an individual taxonomizes more abstract categories, outlining and delimiting specific categories becomes more problematic. Simple taxonomic structures are frequently used in AI programs. For instance, [[WordNet]] is a resource including a taxonomy, whose elements are meanings of English words. [[Web mining]] systems used to collect commonsense knowledge from Web documents focus on taxonomic relations and specifically in gathering taxonomic relations.<ref name="Davis Marcus"/>