He does show, however, that actually a nonlinear representation is harmful everywhere but in the stem, for example, leading to duplication of rules when coverage is extended to affixed forms (page 112f).
he must weaken his architecture to provide a second stage in which rules postprocess fully linearized verb stems; the same setup is proposed for broken plural formation in nouns, because vowel length and prosodic shape transfer from singular to plural and cannot be read off the components alone.