Probability j and lǜ[ probability]: quantities indicating the probability of something happening. Naturally, the probability of inevitable events is set to 1, the probability of impossible events is set to 0, and the probability of general random events is a number [percentage] between 0 and 1: the probability obtained according to cumulative statistics, for example, the survival probability is 50%. Later, because "probability" was used too much, it became a full member, and now both kinds of writing can be used. They are synonyms. The two are interchangeable.