Sentence:  In this paper a distinction is assumed between full <WSD>syncretism</WSD>, which affects whole morphemes, and partial <WSD>syncretism</WSD>, which affects only some case allomorphs, and also between <WSD>syncretism</WSD> proper and mere loss of a case morpheme. 
Meaning of the word marked with <WSD> tags:  The fusion of different inflexional forms.