While I was trying to improve my latest document with respect to its \qed
symbols at the end of amsthm
's proof
environment i came across an interesting point. Assume the proof ends with some formula, that is finally representing the form the lemma/theorem proposes.
Something like
\documentclass{scrartcl}
\usepackage[fleqn]{amsmath}
\usepackage{amsthm,amstext,amsfonts,bm,amssymb}
\begin{document}
\begin{proof}
...
\begin{equation}
\begin{split}
A&= B \\
&= C\\
&= D&\qedhere
\end{split}
\end{equation}
\end{proof}
\end{document}
While using \qedhere
just in equation
or align
would put the symbol below any number (or at least to that side for euqation*
), here the symbol is placed far to the left, even with using the additional column with &
. Putting it after \end{split}
would center it vertically with respect to the three columns, so my question is
How can I get the \qed
symbol to the bottom right (text border) of an (equation-)split environment?
Where I would prefer a global solution for all split
s where I mention \qedhere
at the end.
Best Answer
the best approach in this particular case is to use
align*
, as that behaves well with\qedhere
since each line is treated separately. (any of the multi-line options that treats lines separately should work equally well.)this isn't always ideal --
cases
, for example, will always force the tombstone to the center vertically -- but the request has been made often enough to place the tombstone on the last line, that it should be considered as a possible option. i am adding it to the formal list of requests.as noted elsewhere, with flush left equations and equation numbers on the right, there is a built-in conflict. that is why ams document classes default to using equation numbers on the left.