Math.Combinatorics.IncidenceAlgebra
data Interval a
ivPoset
intervalIsos
isIntervalIso
intervalIsoMap
intervalIsoClasses
unitIA
basisIA
zetaIA
muIA1
muIA
invIA1
invIA
numChainsIA
etaIA
numMaximalChainsIA
muC
muB
muL
toIsoClasses
toIsoClasses'