Abstract: Apparatus (2) for receiving a phallus (4), which apparatus (2), comprises a frame (6), a diaphragm (8) supported by the frame (6), and an aperture (10) in the diaphragm (8), the apparatus (2) being such that: (i) the diaphragm (8) is made of a stretchable material; (ii) the stretchable material is such that the aperture (10) is stretchable radially to enable the phallus (4) to extend through the diaphragm (8), the diaphragm (8) is stretchable transversely to extend along the phallus (4) but only for a short length substantially less than the length of the phallus (4), the part of the diaphragm (8) in contact with the phallus (4) acts with a compressible force sufficient to provide the phallus (4) with sexual stimulation, and the diaphragm (8) returns to its original shape after use; and the diaphragm (8) is substantially flat when not in use.

Abstract: Apparatus (2) for receiving a phallus (4), which apparatus (2), comprises a frame (6), a diaphragm (8) supported by the frame (6), and an aperture (10) in the diaphragm (8), the apparatus (2) being such that: (i) the diaphragm (8) is made of a stretchable material; (ii) the stretchable material is such that the aperture (10) is stretchable radially to enable the phallus (4) to extend through the diaphragm (8), the diaphragm (8) is stretchable transversely to extend along the phallus (4) but only for a short length substantially less than the length of the phallus (4), the part of the diaphragm (8) in contact with the phallus (4) acts with a compressible force sufficient to provide the phallus (4) with sexual stimulation, and the diaphragm (8) returns to its original shape after use; and the diaphragm (8) is substantially flat when not in use.

Abstract: One embodiment of the present invention includes a computer operable to represent a physical system with a graphical data structure corresponding to a matroid. The graphical data structure corresponds to a number of vertices and a number of edges that each correspond to two of the vertices. The computer is further operable to define a closed pathway arrangement with the graphical data structure and identify each different one of a number of fundamental cycles by evaluating a different respective one of the edges with a spanning tree representation. The fundamental cycles each include three or more of the vertices.