标题： It{ô}-Föllmer 公式 -- 非标准情况 显示英文标题

标题： The It{ô}-Föllmer formula -- nonstandard cases

摘要： 本说明的目的是证明Itô-Föllmer公式，适用于在某个分划序列上可能以“最弱”方式具有二次变差的càdlàg路径。 这意味着，例如，我们不要求二次变差的跳跃恰好发生在路径本身跳跃的时间点，或者要求二次变差在所有时间点都存在。 此外，我们处理的分划比Föllmer使用的具有消失网格的分划更加一般，同时也放松了其他相关文献中对分划序列施加的限制。 显示英文摘要

摘要： The purpose of this note is to prove the It{\^o}-F\"ollmer formula for the c\`adl\`ag paths possessing quadratic variation in a possibly ``weakest'' sense along some sequence of partitions. By this we mean, for example, that we do not require the jumps of the quadratic variation to occur exactly at the times when the path itself jumps or that the quadratic variation exists at all time instances. Moreover, we deal with more general partitions than partitions with vanishing mesh used by F\"ollmer, also relaxing restrictions imposed on a sequence of partitions in other related literature.