A collection of common nondeterministic and/or combinatorial operations. Many operations are intended to operate on sets. The representation of these sets is not hidden; rather sets are represented as lists. Ideally these lists contains no duplicate elements and the order of their elements cannot be observed. In practice, these conditions are not enforced.
Author: Sergio Antoy (with extensions by Michael Hanus)
Version: January 2019
permute
:: [a] > [a]
Compute any permutation of a list. 
subset
:: [a] > [a]
Compute any sublist of a list. 
allSubsets
:: Ord a => [a] > [[a]]
Compute all the sublists of a list. 
splitSet
:: [a] > ([a],[a])
Split a list into any two sublists. 
sizedSubset
:: Int > [a] > [a]
Compute any sublist of fixed length of a list. 
partition
:: [a] > [[a]]
Compute any partition of a list. 
Compute any permutation of a list.

Compute any sublist of a list. The sublist contains some of the elements of the list in the same order.

Compute all the sublists of a list.

Split a list into any two sublists.

Compute any sublist of fixed length of a list.
Similar to

Compute any partition of a list. The output is a list of nonempty lists such that their concatenation is a permutation of the input list. No guarantee is made on the order of the arguments in the output.
