 This would have been a waste of precious resources, however, and was no more an option now than it had been before.Petrus, who often divided his breves into as many as seven semi-breves, developed the dot of division (punctum divisionis), which are dots placed in between semi-breves to group them; thus a series of five semi-breves separated by dots from those surrounding them would be understood by the reader as occurring in the space of one breve.In later, 15th and 16th century notation, confusion between dots of division and the later innovation of dots indicating extended note values creates transcription problems for editors, but it is usually possible to tell from context, as well as prevailing tempus and prolation, which is meant; indeed, the dot of division is rarely required, since a run of semi-breves coming between two ligatures is clearly a grouping.