On 18 April 2012 14:26, Stefan Holdermans <ste...@vectorfabrics.com> wrote: > 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 -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com http://IvanMiljenovic.wordpress.com _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
