Def: A pseudomanifold with boundary is a simplicial complex with the following properties: • it is pure of some dimension 𝑑 (all of its facets are 𝑑-dimensional) • every (𝑑 − 1)-dimensional simplex is the face of at most two facets • for every two facets 𝑆 and 𝑇 , there is a sequence of facets 𝑆 = 𝑓_0, 𝑓_1, ..., 𝑓_𝑛 = 𝑇 such that for each 𝑖, 𝑓_𝑖 and 𝑓_{𝑖−1} intersect in a (𝑑 − 1)-simplex