Coalescence as autosegmental spreading and delinking

Phonological coalescence, understood as a type of synchronic alternation in which two phonological elements seem to fuse into one, presents a prima facie challenge for versions of Optimality Theory that assume the principle of containment. If all underlying material has to be present in the output form, replacing two input elements with a single output element is not straightforward. I argue that, under the assumptions of Autosegmental Coloured Containment Theory, a distinct operation of coalescence is unnecessary, as all major types of coalescence patterns can be analysed in terms of (i) adding new association lines between some autosegmental nodes, and (ii) the underparsing of other nodes, leading to their phonetic non-realisation. The proposed analysis accurately reflects the heterogeneity of coalescence alternations, which are shown to fall into three different types.