Infinite Enumerated Sets

AUTHORS:

• Florent Hivert (2009-11): initial revision.

class sage.categories.infinite_enumerated_sets.InfiniteEnumeratedSets(base_category)

Bases: sage.categories.category_with_axiom.CategoryWithAxiom_singleton

The category of infinite enumerated sets

An infinite enumerated sets is a countable set together with a canonical enumeration of its elements.

EXAMPLES:

sage: InfiniteEnumeratedSets()
Category of infinite enumerated sets
sage: InfiniteEnumeratedSets().super_categories()
[Category of enumerated sets, Category of infinite sets]
sage: InfiniteEnumeratedSets().all_super_categories()
[Category of infinite enumerated sets,
 Category of enumerated sets,
 Category of infinite sets,
 Category of sets,
 Category of sets with partial maps,
 Category of objects]

class ParentMethods

Bases: object

list()

Returns an error since self is an infinite enumerated set.

EXAMPLES:

sage: NN = InfiniteEnumeratedSets().example()
sage: NN.list()
Traceback (most recent call last):
...
NotImplementedError: cannot list an infinite set

random_element()

Returns an error since self is an infinite enumerated set.

EXAMPLES:

sage: NN = InfiniteEnumeratedSets().example()
sage: NN.random_element()
Traceback (most recent call last):
...
NotImplementedError: infinite set

TODO: should this be an optional abstract_method instead?