The linguistic literature abounds with discussions of phi-feature inflection. The formalist tradition has, in a variety of ways, approached this phenomenon predominantly in terms of an agreement relationship between two terms of a syntactic structure—for instance, the subject and the finite verb (typically showing agreement for person and number), or the object and a past participle (which, e.g. in the Romance languages, may agree for number and gender, but not for person). But not all these agreement relationships affect all phi-features equally, which raises the question of whether there is to be a unified approach to phi-features in general.