Therefore, when we store a discrete differential form it’s not enough to just store a number:
we also have to specify a canonical orientation for each element of our mesh, corresponding to the
orientation we used during integration. For an edge we’ve already seen that we can think about
orientation as a little arrow pointing from one vertex to another—we could also just think of an
edge as an ordered pair (i, j), meaning that we always integrate from i to j.
More generally, suppose that each element of our mesh is an oriented k-simplex s, i.e., a collection
of k + 1 vertices pi 2 Rn given in some fixed order (p1, . . . , pk+1). The geometry associated with s