A problem checker architecture that monitors user progress during a problem-solving process and assists the user through the process using common human methods of solving the problem. Two or more base stations support a predetermined radio access scheme in common. The specifying device specifies a viewpoint and a sight line direction to look down a picture based on the first and second signals outputted by the operating device. In addition, many of the devices and systems of the invention are adapted to be reversible and removable from the patient at any point without interference with or trauma to internal tissues. When wire cutter is not used, accommodation of used wire electrode can be enhanced. The composition exhibits good antistatic and repellency characteristics.