#5314: [with patch, needs review] The empty permutations exists !
---------------------------+------------------------------------------------
Reporter: hivert | Owner: hivert
Type: defect | Status: new
Priority: major | Milestone: sage-3.4.1
Component: combinatorics | Keywords: permutations, empty
---------------------------+------------------------------------------------
Right now sage consider that there is no empty permutations.
{{{
sage: [] in Permutations()
False
}}}
There seems to be an agreement about the fact that the empty permutations
exists ! Indeed there exists an empty set, and there exits exactly one
function from the empty set to itself which is clearly bijective.
The patch solve this defect:
{{{
sage: import sage_emacs as emacs
sage: [] in Permutations()
True
sage: Permutations(0).list()
[[]]
sage: Permutations(0).count()
1
}}}
Author: Florent Hivert
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/5314>
Sage <http://sagemath.org/>
Sage - Open Source Mathematical Software: Building the Car Instead of
Reinventing the Wheel
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en
-~----------~----~----~----~------~----~------~--~---
