Abstract: In an arithmetic apparatus (10), a prediction state determination unit (11) determines a plurality of prediction states for each of a plurality of candidate actions that can be executed in a first state by using a plurality of transition information units. A degree of variation calculation unit (12) calculates degrees of variation of the plurality of prediction states determined for each of the plurality of candidate actions by the prediction state determination unit (11). A candidate action selection unit (13) selects some of the candidate actions among the aforementioned plurality of candidate actions based on the plurality of degrees of variation calculated by the degree of variation calculation unit (12).