TEI P3 (pp. 865-66) uses the floating tag <argument>..</argument>. This deprives the argument of a structural role in the work.
<pmdv type="argument"> <heading> THE ARGUMENT. </heading> <p> This first Book proposes, first in brief, the whole Subject, {{}Mans disobedience, and the loss thereupon of Paradise wherein he was plac't:{}} Then touches ... </pmdv>
<pmdv argument> <tt heading> THE ARGUMENT. <tt argument > <p> This first Book proposes, first in brief, the whole Subject, {Mans disobedience, and the loss thereupon of Paradise wherein he was plac't:} Then touches ... </pmdv>