{"type":"rich","version":"1.0","title":"6svjszwk wrote","author_name":"6svjszwk (npub1sx…jszwk)","author_url":"https://yabu.me/npub1sxgnpqfyd5vjexj4j5tsgfc826ezyz2ywze3w8jchd0rcshw3k6svjszwk","provider_name":"njump","provider_url":"https://yabu.me","html":"关键的前提条件之一是有限方差，问题是如何事前知道方差是有限的？"}