4

I want to define a simple environment to enclose my proofs, actually I just wanted to put a little square right at the end. So, I made this new environment definition:

\newenvironment{Proof}{ \flushleft \textbf{PROOF}}{\rule{1ex}{1ex}}

When I use this environment to enclose simple text, then I get the little square right at the end, after the last character. The problem is when I enclose an enumerate environment because it adds a new line and put the little square at the beginning. In this case my problem is both I don't want the new line and also I need the square at the right ending of the margin. If I consider it this way

\newenvironment{Proof}{ \flushleft \textbf{PROOF}}{\begin{flushright} \rule{1ex}{1ex} \end{flushright}}

then a new line is always added.

1
  • 1
    I would consider doing what barbara suggests, there's a well-done proof environment. You suggest using a black box (\rule{1ex}{1ex}), this can be achieved too, by redefining \qedsymbol.
    – yo'
    Commented Feb 7, 2013 at 20:23

1 Answer 1

10

amsthm automatically puts a box (an open box, but that can be redefined) flush right at the end of the last line of proof. if the proof ends with a display or a list, then \qedhere can be used just before the end of that environment to move the box to the proper line.

to start the enumerated list on a new line after the proof header, enter it as

\begin{proof}
 \leavevmode
 \begin{enumerate}
 ...

documentation is available with texdoc amsthm (if you are using a system based on tex live) or by visiting the page and clicking on the line "AMS theorem package user's guide".

to redefine the qed box,

\renewcommand{\qedsymbol}{...}

to change the main proof header,

\renewcommand{\proofname}{Whatever}

(thanks, egreg.)

for a one-time variant, just take advantage of the optional argument:

\begin{proof}[Proof of the XYZ theorem]
3
  • Great! how can exactly redefine the box? Commented Feb 7, 2013 at 20:25
  • Perfect!. Just a last question, sorry because I'm so new on this. How can I change the format of word "proof". Commented Feb 7, 2013 at 20:44
  • 2
    @DanielaDiaz \renewcommand{\proofname}{Whatever} if you don't use babel. If you use babel with language spanish (just as an example), \addto\captionsspanish{\renewcommand{\proofname}{Whatever}}
    – egreg
    Commented Feb 7, 2013 at 21:05

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .