However, as the probability of the joined event of numerous features (X_1..n) \((X_{1..n})\) is usually zero or close to zero, and thus not suitable for probability estimates, there is an expanded form of this equation that allows to estimate the joined events from the independent events.然而，在此某特定條件下因為樣>本數過少，時常為0或趨近於0，於是利用一個擴大範圍的算式使得其他的墓也能被計算，只有明墓作為一個獨立事件\cite{wiki:bayes}。