extends_category(Category1, Category2) extends_category(Category1, Category2, Scope)
Enumerates, by backtracking, all pairs of categories such that the first one extends the second. The relation scope is represented by the atoms public, protected, and private.
extends_category(?category_identifier, ?category_identifier) extends_category(?category_identifier, ?category_identifier, ?scope)
type_error(category_identifier, Category1)type_error(category_identifier, Category2)type_error(atom, Scope)domain_error(scope, Scope)| ?- extends_category(basic, Category). | ?- extends_category(Category, extended, private).
current_category/1, complements_object/2, imports_category/2-3