It is common to place a
\qed-Box at the end of a theorem statement (or lemma, corollary, …) if we give no proof for that statement.
How can I do this in LaTeX? If I place a qed-box at the end of the statement there is an additional linebreak, which is inacceptable formating.
if you are using
amsthmor an ams document class, this problem is addressed by an item in the ams author faq. this in turn links to an example document (that's the input; the output is also present) that covers quite a few of the possible situations in which such a marker could be wanted. the most extreme situations require some manual effort, but i believe that nearly all reasonable possibilities (including the non-proof ending with a display) are covered.