Interior edges not corretly selected for volume meshes when using 'in' predicate

[cmuenger]

Interior edges are not correctly selected using the 'in' predicate to subtract the boundary edges from all edges in a tetrahedral mesh.

Steps to reproduce:

using CompScienceMeshes
using PlotlyJS

M =  tetmeshsphere(1.0,0.5)
edges = skeleton(M,1)
bnd = boundary(M)
bnd_edges = skeleton(bnd,1)
int_edges = submesh(!in(bnd_edges),edges)

plot(wireframe(int_edges))

Possible workaround by using 'overlap' predicate:

using CompScienceMeshes
using PlotlyJS

M =  tetmeshsphere(1.0,0.5)
edges = skeleton(M,1)
bnd = boundary(M)
bnd_edges = skeleton(bnd,1)
overlap = (m,i) -> overlap_gpredicate(bnd_edges)(chart(m,i))
int_edges = submesh(!overlap,edges)

plot(wireframe(int_edges))