On 18 April 2012 14:26, Stefan Holdermans
I am pleased to announce the first release of signed-multiset, which implements an abstract datatype for multisets with negative membership.
The package can be obtained from
http://hackage.haskell.org/package/signed-multiset-0.1
As always, feedback is welcome.
Cheers,
Stefan
signed-multiset-0.1 -------------------
Multisets (or bags) are sets in which elements may occur more than once. The number of times an element occurs in a multiset is called its multiplicity.
This package provides an efficient implementation of so-called signed multisets, which generalise multisets by allowing for negative membership. That is, elements in a signed multiset can have negative multiplicities.
Wait, something can be not in the multiset more than once? :o
See also: Wayne D. Blizard. Negative membership. Notre Dame Journal of Formal Logic/, 31(3):346--368, 1990. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
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