ntheorem.pdf. - Mirrors.med.harvard.edu

\lendmultline The multline environment has two different \end commands, depending if
the equation numbers are set on the left or on the right:
392 \def\lendmultline@{%
393 \global\@eqnswfalse\tag@false\tagsleft@false
394 \rendmultline@}
End of multline environment if tags are set to the left: in this case, the
last line of a multline does not contain a tag. Thus the situation of setting
an endmark tag at the right is faked:
Lines 393, 394: display no equation number, don’t set an equation tag (but
use the tag mechanism for the end mark - see \TagsPlusEndmarks and
\SetOnlyEndMark), set it at the right, and call \rendmultline.
\rendmultline \rendmultline also uses the augmented tags:
\endmathdisplay
395 \def\rendmultline@{%
396 \TagsPlusEndmarks %