Self-referential discs and the light bulb lemma

We show how self-referential discs in 4-manifolds lead to the construction of pairs with a common geometrically dual sphere which are homotopic rel $\partial$, concordant and coincide near their boundaries, yet not properly isotopic. This occurs manifolds without 2-torsion fundamental group, e.g. boundary connect sum $S^2\times D^2$ $S^1\times B^3$, thereby exhibiting phenomena seen spheres. On other hand we that two such isotopic $\partial$ if manifold is simply connected. construct D^2\natural S^1\times B^3$ embedded 3-ball $z\_0\times but B^3$.