isShelling -- determines whether a list represents a shelling of a simplicial complex.

Synopsis

Usage:

b = isShelling(P)
Inputs:
- P, a list, A list of lists of integers. Each list of integers is a facet of the complex and the order is a possible shelling.
Outputs:
- b, a Boolean value, true if and only if P is a shelling.

Description

An ordering $F_1,..F_d$ of the facets of a simplicial complex $P$ is shellable if $(F_1 \cup .. \cup F_{k-1}) \cap F_k$ is pure of dim$F_k -1$ for all $k = 2,..,d$. Determines if a list of faces is a shelling order of the simplicial complex.

i1 : P = {{1, 2, 3}, {1, 2, 5}};

i2 : isShelling(P)

o2 = true

i3 : Q = {{1,2,3},{3,4,5},{2,3,4}};

i4 : isShelling(Q)

o4 = false

Ways to use isShelling :

isShelling(List)

For the programmer

The object isShelling is a method function.