A roller bit is provided having super-abrasive inserts on cutting portions to assure that the bit will maintain cutting efficiency. The route searching device detects an optimum route among possible routes from a first point to a second point, on the basis of link costs that are set for a plurality of links constituting the possible routes. Two writing orders for cells of the buffer memory array are used in turn, each being combined with a different reading order for the cells. The method includes applying a drain voltage of first polarity type on the drain region and applying a control gate voltage of a first conductivity type on the control gate. The opening section is formed so as to include at least a first tilted side extending in a direction tilted relative to an axis of the second exhaust pipe section. The example assembly can include an anchoring pin coupled to the structural support, and a cooking surface assembly, and a vertical adjustment mechanism coupled to the structural support member and the cooking surface assembly, the vertical adjustment mechanism allowing the spatial position of the cooking surface assembly to be vertically modified.