Computation and simulation of an interface of a fluid in a space which is represented by a grid having cells is improved with respect to robustness by reconstructing unknown populations at front nodes, i. A method of controlling pests, a process for the preparation of the composition, its use and plant propagation material treated with it, and the use of the compound of the formula for the preparation of the composition, are described. The hopper is mounted to the apparatus on a slide assembly, which allows the hopper to be moved to a second position at which particles may be discharged from the hopper exit away from the particle feeder. The playing history data card information of cards possessed by each of the members is described; and a process of managing the slave game is provided, the process including a card-issuing process in which a member-avatar card that is used for playing the card game and is derived from each member is issued and is possessed by any of the members.