Sch 20B para 30
Paragraphs 31 to 33 apply where a person (“P”) is serving two or more sentences of imprisonment and— (a) the sentences were passed on the same occasion, or (b) where they were passed on different occasions, the person has not been released under Part 2 of the 1991 Act or under this Chapter at any time during the period beginning with the first and ending with the last of those occasions.