A system and method for generating a model for simulating systems of reacting species comprising receiving a plurality of reaction formulas, determining a reaction rate expression for each of the received reaction formulas, and generating a model for simulating systems of reacting species using the received reaction formulas and the determined reaction rate expressions. The portable terminal includes a guide member mounted in a first closed area provided on one surface of the first housing and always covered up by the second housing, and a slide member mounted on one surface of the second housing and sliding over the first housing by being guided by the guide member. The quantity or quantities which correspond to the other dimension or dimensions are fixed values. The device uses the venturi effect to create the lowered pressure. In another aspect of the present invention, the sealing fin has a rectangular configuration with a hinged portion. Thus, even if a large current is caused to flow through the output transistor, the output transistor can be made to operate for switching at a high speed.