Monotonicity of the zeros of a cross product of Bessel functions

A fastener clip having a plurality of fasteners for use in attaching a button to a garment or a piece of fabric. In a preferred embodiment, the fastener clip comprises a plurality of fasteners, each fastener being a flexible U-shaped filament having a foot at each end. The filament portion of the fastener is preferably rectangular in cross-section and has a non-uniform thickness, i.e., being thinner at the ends and thicker in the arcuate region, to maximize the strength of the fastener. The feet are appropriately dimensioned so that they may be inserted into a desired garment through a pair of button holes of conventional size and thereafter be retained by the underside of the garment. Each foot has rounded ends, a flat top surface and a compact size to minimize irritation with a person's skin. The fastener clip also comprises a pair of runner bars, each fastener being connected to the pair of runner bars by a pair of severable connector posts. The connector posts are attached to the outer sides of the fastener feet, as opposed to the bottoms thereof, so that, when they are severed, they will not create burrs in areas where they are likely to come into contact with a person's skin.