Positional markedness in Catalan word-final deletion

In Catalan, there are two processes of word-final deletion: /n/-deletion and /r/-deletion. Their contexts are very similar: word-final /n/ and /r/ are deleted if they are preceded by a stressed vowel. But the difference between these processes is that /r/ is deleted before the plural suffix, while /n/ is not. In this paper, I propose an unitary OT analysis of the deletion phenomena in Catalan arguing for the positional markedness constraints. It is argued that the universal ranking of the stressed-syllable-specific version of the margin sonority constraints accounts for the similarity and the difference between two deletion processes.