If magnitude of any term is complete or total, then it is said that, that term is distributed. If magnitude is incomplete, then that term is undistributed. Any term is distributed only when the entire term (set) is either included in or excluded by another term (set). This is another way of explicating what complete magnitude means.
All universal propositions distribute subject whereas no particular propositions distribute subject. Just as distribution is explicated, undistribution also must be explicated. Any term is undistributed when inclusion of one term in another or exclusion of one term from another is partial. If subject has to be undistributed, then, it is necessary that the proposition should either include or exclude only ‘some’ members. When do we say or when are we allowed to use ‘some’? Let the magnitude of S be x. Let S* (to be read s-star) denote the part of s, which is included in or excluded by a proposition.