They don’t know there are other resident monks who haven’t arrived. Perceiving that they’re acting according to the Teaching and the Monastic Law, perceiving that the assembly is complete although it’s not, they do the invitation ceremony. When they’ve just finished, and only some members of the gathering have left, an equal number of resident monks arrive. In such a case, the invitations of those who already have invited are valid, and the late arrivals should invite in the presence of the others. There’s no offense for those who already have invited. On the invitation day, five or more resident monks may have gathered together in a certain monastery. They don’t know there are other resident monks who haven’t arrived. Perceiving that they’re acting according to the Teaching and the Monastic Law, perceiving that the assembly is complete although it’s not, they do the invitation ceremony.