A conversational trading system allows a plurality of instruments, for example financial instruments such as foreign exchange products to be traded from a single user interface. The cylindrical part extends over substantially a half circumference of an equatorial edge of the hemispherical part and is defined by a plane inclined on the equatorial plane. When the vehicle travels at high speeds, the actual value comparison road friction coefficient estimating section renders a road friction coefficient estimating value by a yaw rate comparison method gradually close to a road friction coefficient of an asphalted road surface. The third layer overlies the second layer and includes a polymeric material. The renderview host may then provide the bitmap to a backing store associated with a display device for display to a user. It is considered that a peeling layer tends to be peeled from a substrate because the stress is applied to a peeling layer due to the difference in thermal expansion coefficient between a substrate and a peeling layer, or because the volume of a peeling layer is reduced and thus the stress is applied thereto by crystallization of the peeling layer due to heat treatment.