多條件機率:多條件機率公式[朗讀]

p(w|s)=p(w,s)/p(s)p(w|r,s)p(r|s)=[p(w,r,s)/p(r,s)][p(r,s)/p(s)]=p(w,r,s)/p(s)p(w|~r,s)p(~r|s)=[p(w,~r,s)/p(~r,s)][p(~r,s)/p(s)]=p(w,~r,s)/p(s)同時:p(w,r,s)/p(s)+p(w,~r,s)/p(s)=[p(w,r,s)+p(w,~r,s)]/p(s)=p(w,s)/p(s)所以p(w|s)=p(w|r,s)p(r|s)+p(w|~r,s)p(~r|s)四個變量時用相同方法證明,你自己證明吧。