1993 年 8 巻 5 号 p. 619-627
Even we human cannot solve the frame problem. Nevertheless, in daily life we can act as if there is no such problem, because we use some heuristics to bypass it. In this paper, we propose that the concept of causality is the heuristics. We also claim that temporal ordering in causal relation is not essential. Any partial ordering suffices but once the order is fixed, it should be followed even in reverse order reasoning such as inferring the past from future. We formalize causal reasoning and apply it to YSP.