and x u2266 dx u2266 y are met is recognized at step s 403 the trigger target data d 1 is monitored at step s 404 it is judged whether or not the trigger target data d 1 satisfies the trigger condition a u2266 d 1 u2266 b recognized at step s 402 the process execution proceeds to step s 405 when the result of the judgment is yes and it returns to step s 403 when the result is no at step s 405 trigger target data d 2 is monitored at step s 406 it is judged whether or not the trigger target data d 2 satisfies the trigger condition c u2266 d 2 u2266 d recognized at step s 402 the process execution proceeds to step s 407 when the result of the judgment is yes and it returns to step s 403 when the result is no at step s 407 the trigger target data dx is monitored at step s 408 it is judged whether or not the trigger target data dx satisfies the trigger condition x u2266 dx u2266 y recognized at step s 402 the process execution proceeds to step s 409 when the result of the judgment is yes and it returns to step s 403 when the result is no at step s 409 acquisition of observational data is.