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Triplets :: Triplet

Triplet -- triplet


A Triplet is a list consisting of three degree sequences, each of which is a list of increasing integers. These three degree sequences fulfill certain compatibility conditions. There are two different but equivalent versions:

1. A degree triplet, see Definition 2.9 in math.AC/1207.2071 "Triplets of pure free squarefree complexes"

2. A homology triplet, see Definition 5.4 in math.AC/1212.3675 "Zipping Tate resolutions and exterior coalgebras"

The routines isDegreeTriplet and isHomologyTriplet checks if a triplet fulfills the compatibility conditions for degree and homology triplets, respectively. The routine toHomology converts from a degree triplet to a homology triplet, and the routine toDegree converts from a homology triplet to a degree triplet.

Functions and methods returning an object of class Triplet :

Methods that use an object of class Triplet :

For the programmer

The object Triplet is a type, with ancestor classes List < VisibleList < BasicList < Thing.