Too much space between the math expression and the symbol at the end of a statment of theorem, remark etc

Question

I've added a diamond symbol to the end of my theorem (and other) environments:

However, when I use any display math at the end of the theorem, the diamond gets set too low:

Is there some way to get the diamond up, automatically so it is aligned (or almost aligned) with the end of the math expression? Something like this (I used \tag*{\diamond}):

\documentclass[letterpaper,11pt]{book}
\usepackage[english]{babel}
\usepackage[T1]{fontenc}
\usepackage{amsmath}
\usepackage{dsfont}
%im using this font (in case it is important)
\usepackage{tgbonum}
\newcommand\hmmax{0}
\newcommand\bmmax{0}
\usepackage{helvet}
\renewcommand{\familydefault}{\sfdefault}
%using the package amsthm to define theorems lemmas, corolaries etc.
\usepackage{amsthm}
\newtheorem{thrm1}{Theorem}[section]
\newtheorem{remark1}[thrm1]{Remark}
\newtheorem{prop1}[thrm1]{Proposition}
%this new commands let me end every statment of a theorem, remark or proposition with any symbol, in this case i'm using "$\diamond$"
\newcommand{\thmsymbol}{$\diamond$}
\newenvironment{thrm}{\begin{thrm1}%
  \renewcommand{\qedsymbol}{\thmsymbol}\pushQED{\qed}}%
  {\popQED\end{thrm1}}
\newenvironment{remark}{\begin{remark1}%
  \renewcommand{\qedsymbol}{\thmsymbol}\pushQED{\qed}}%
  {\popQED\end{remark1}}
\newenvironment{prop}{\begin{prop1}%
  \renewcommand{\qedsymbol}{\thmsymbol}\pushQED{\qed}}%
  {\popQED\end{prop1}}
\begin{document}
\section*{So, my problem is the following.}
\begin{thrm} Every end of a theorem, proposition, remark etc, is marked with the symbol ``$\diamond$''.
\end{thrm}
\begin{remark}
As you can see, the diamond symbol is positioned immediately at the end of the sentence. I mean, it is just right here $\rightarrow\rightarrow\rightarrow\rightarrow\rightarrow$
\end{remark}
\section*{My problem is when I use math mode}
\begin{prop} When I use math mode, the position of the $\diamond$ is too low
    $$\int_0^1 x , dx = \frac{1}{2} \quad \text{i mean, it goes waaaay down: } \rightarrow\rightarrow\rightarrow\rightarrow\rightarrow\rightarrow\rightarrow \searrow $$
\end{prop}
My question is: \textbf{is there some way to get the diamond up, automatically?} aligned (or almost aligned) with the end of the math expression, something like this:
\begin{prop1} Here is Euler's formula 
\begin{align}
e^{ix} = \cos (x) + i \sin (x) \quad\quad \forall x \in \mathds{R} \tag{$\diamond$}
\end{align}
\end{prop1}
And I can continue without any problem, instead of dealing with: 
\begin{prop} Here is Euler's formula 
\begin{align}
e^{ix} = \cos (x) + i \sin (x) \quad\quad \forall x \in \mathds{R} 
\end{align*}
\end{prop}
\noindent Too much space between the math expression and the diamond symbol!
\end{document}

Have you read the amsthm user guide? It explains the use of \qedhere to avoid the kind of spacing you're encountering when a proof ends with display math. You might try that. (I haven't vetted the code changes to see if they do the same thing.) But \qedhere doesn't work with $$, so you should change that to \[...\] or `equation*. — barbara beeton, Jan 14 '24 at 23:58
This question may be helpful: How to make all theorem-like environments have an ending symbol? — barbara beeton, Jan 15 '24 at 00:02

score 4 · Accepted Answer · answered Jan 15 '24 at 06:35

You want \qedhere for the cases when the QED symbol has to appear in a math display or at the end of a list (enumerate or itemize).

However, you mustn't use $$: see Why is \[ ... \] preferable to $$ ... $$?. Here it's not just “preferable”, it is crucial. Any standard amsmath display environment accepts \qedhere.

\documentclass[letterpaper,11pt]{book}
\usepackage{amsmath}
\usepackage{amsthm}
\newtheorem{thrm1}{Theorem}[section]
\newtheorem{remark1}[thrm1]{Remark}
\newtheorem{prop1}[thrm1]{Proposition}
\newcommand{\thmsymbol}{$\diamond$}
\newenvironment{thrm}{\begin{thrm1}%
  \renewcommand{\qedsymbol}{\thmsymbol}\pushQED{\qed}}%
  {\popQED\end{thrm1}}
\newenvironment{remark}{\begin{remark1}%
  \renewcommand{\qedsymbol}{\thmsymbol}\pushQED{\qed}}%
  {\popQED\end{remark1}}
\newenvironment{prop}{\begin{prop1}%
  \renewcommand{\qedsymbol}{\thmsymbol}\pushQED{\qed}}%
  {\popQED\end{prop1}}
\begin{document}
\section*{So, my problem is the following.}
\begin{thrm}
Every end of a theorem, proposition, remark etc, is marked with the symbol ``$\diamond$''.
\end{thrm}
\begin{remark}
As you can see, the diamond symbol is positioned immediately at the end of the sentence. 
I mean, it is just right here $\rightarrow\rightarrow\rightarrow\rightarrow\rightarrow$
\end{remark}
\section*{My problem is when I use math mode}
\begin{prop}
When I use math mode correctly, the position of the $\diamond$ is perfect
[
\int_0^1 x , dx = \frac{1}{2} \qedhere
]
\end{prop}
\end{document}

I only left the relevant parts of the document.

Too much space between the math expression and the symbol at the end of a statment of theorem, remark etc

1 Answers1