The topic of this paper remains interesting to me: how are the triple points
of an immersion immersed in the double manifold, and how is the double-manifold
immersed in the manifold itself? And which regular homotopy classes of immersions
can be easily constructed, and how can one determine the regular homotopy class from
the double-set alone? The paper was written when I was in grad school, and hence
takes a naive and simple approach to the problems, which I hope is therefore accessible.
