證2+證3=證5≡證=一 (二重證據法加三重證據法等於五重證據法當且僅當應歸一的證據) : 再論中國古代學術證據法 = Evidence2 + evidence3 = evidence5 ≡ evidence = one (double evidence plus triple evidence equals quintuple evidence if and only if evidence is unitary) : further remarks on the evidential method for scholarship on ancient China