Predecessor, Successor and Segmenting Function

We say that y is a predecessor of x, in symbols: y p x, if and only if y is an elementary segment immediately preceding x in time and forming together with x a phonetic chain. Formally: https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429466816/c51499bf-8d6f-413a-8894-096dbf3fef0c/content/pg49.tif"/>