coincident-root-loci-0.2: Equivariant CSM classes of coincident root loci

Safe HaskellNone
LanguageHaskell2010

Math.RootLoci.Geometry.Mobius

Contents

Description

Mobius inversion for the coarsening poset of partitions

Synopsis

Documentation

newtype Partition :: * #

A partition of an integer. The additional invariant enforced here is that partitions are monotone decreasing sequences of positive integers. The Ord instance is lexicographical.

Constructors

Partition [Int] 

The refinement poset of partitions

closures

fastClosure :: Partition -> Set Partition Source #

Fast computation of a single closure

fastAntiClosure :: Partition -> Set Partition Source #

Fast computation of a single "anticlosure" (opposite poset)

closureSet :: Partition -> Set Partition Source #

Caches and reuses all closures (lazily), this is the fastest version

closureSet' :: Partition -> Set Partition Source #

The closure without the stratum itself

Mobius function

zetaOf :: Partition -> ZMod Partition Source #

Zeta function of the refinement poset

mobiusOf :: Partition -> ZMod Partition Source #

Mobius function of the refinement poset

helpers

firstLevelDown :: Partition -> [Partition] Source #

Merging two parts

firstLevelUp :: Partition -> [Partition] Source #

Splitting one part into two

set partitions