combinat::setPartitionsOrdered – ordered set partitions of a set

The library combinat::setPartitionsOrdered provides functions for counting, generating, and manipulating ordered set partitions.

→ Examples

Related Domains:

combinat::compositions, combinat::setPartitions

Details:

An ordered set partition  p of a set s is a partition of s, into subsets called parts and represented as a list of sets. By extension, an ordered set partition of a nonnegative integer n is the set partition of the integers from 1 to n. The number of ordered set partitions of n is called the n-th ordered Bell number.

 

There is a natural integer composition associated with an ordered set partition, that is the sequence of sizes of all its parts in order.

Entries

"domtype"

The MuPAD domain used to represent set partitions: DOM_LIST

isA – test if an object is an ordered set partition

combinat::setPartitionsOrdered::isA(any type set, <set s, composition c>)

Returns whether set is an ordered set partition.

If the first optional argument s is present, returns whether set is an ordered set partition of s.

If the second optional argument c is present, returns whether set is a set partition of swith parts of sizes given by c.

count – number of ordered set partitions

combinat::setPartitionsOrdered::count(any type set, <composition c>)

Returns the number of ordered set partitions of set whose underlying composition is c.

list – list of ordered set partitions

combinat::setPartitionsOrdered::list(any type set, <composition c>)

Returns the list of ordered set partitions of set whose underlying composition is c.

Example 1:

There are math ordered set partitions of math:

combinat::setPartitionsOrdered::count(3)

math

Here is the list:

combinat::setPartitionsOrdered::list(3)

math

There are math set partitions of math whose underlying partition is math:

combinat::setPartitionsOrdered::list(4,[1,2,1])

math