 More precisely, this type of singularity is a closed arc consisting of intersection points of the disk with itself, such that the preimage of this arc consists of two arcs in the disc, one completely in the interior of the disk and the other having its two endpoints on the disk boundary.A slice disc "M" is a smoothly embedded formula_1 in formula_2 with formula_3.Consider the function formula_4 given by formula_5.