  We obtain complete geometric invariants of cobordism classes of oriented
simple fold maps of (n+1)-dimensional manifolds into an n-dimensional manifold
N in terms of immersions with prescribed normal bundles. We compute that this
cobordism group of simple fold maps is isomorphic to the direct sum of the
(n-1)th stable homotopy group of spheres and the (n-1)th stable homotopy group
of the infinite dimensional projective space. By using geometric invariants
defined in the author's earlier works, we also describe the natural map of the
simple fold cobordism group to the fold cobordism group by natural
homomorphisms between cobordism groups of immersions. We also compute the ranks
of the oriented (right-left) bordism groups of simple fold maps.
