library(kappalab)

## a set function
mu <- set.func(c(0,1,1,1,2,2,2,3))
mu
is.kadditive(mu,2)
is.kadditive(mu,1)

## the Mobius representation of a set function, 2-additive by construction 
a <- Mobius.set.func(c(0,1,2,1,3,1,2,1,2,3,1),4,2)
is.kadditive(a,2)
is.kadditive(a,1)