Thmtools & Mdframed: 0mm Vertical Space Between Examples

by Mei Lin 57 views 
%!TEX TS-program = XeLaTeX
%!TEX encoding = UTF-8 Unicode

\documentclass[11pt,a4paper]{article}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsthm}
\usepackage{thmtools}
\usepackage{mdframed}
\usepackage{lipsum}


\declaretheorem[style=definition,name=Example]{example}

\newenvironment{examplebox}[1][]{%
\begin{mdframed}[backgroundcolor=blue!10, innertopmargin=0.3ex, innerbottommargin=0.3ex, innerleftmargin=0.6em, innerrightmargin=0.6em, #1]
}{\end{mdframed}}


\begin{document}

\lipsum[1]

\begin{examplebox}
  \begin{example}
    This is the first example.
  \end{example}
\end{examplebox}

\vspace{0mm} % Attempt to reduce space

\begin{examplebox}
  \begin{example}
    This is the second example.
  \end{example}
\end{examplebox}

\lipsum[2]

\end{document}

Understanding the Vertical Space Issue Between Examples

Hey guys! So, you're struggling with getting those two examples snug together, huh? You've tried the \vspace{0mm} trick, but it's just not playing ball. Let's dive deep into why this is happening and how we can fix it. Dealing with vertical spacing in LaTeX can sometimes feel like wrestling an octopus – it's tricky, but definitely doable! The core issue here revolves around how LaTeX handles vertical spacing around environments, especially when thmtools and mdframed are in the mix. These packages are fantastic for creating structured and visually appealing content, but they can introduce some default spacing that we need to tame. Essentially, LaTeX adds vertical space above and below environments by default. This is great for readability in general, but not so much when you want things super close together.

First off, let's talk about the default LaTeX spacing. LaTeX has a built-in mechanism for adding space around environments like examplebox and example. This spacing is designed to make your document look clean and professional by preventing elements from bumping into each other. However, in cases like yours, where you want two specific elements to be right next to each other, this default spacing becomes a hindrance. You've already identified this and tried using \vspace{0mm}. While this is a logical step, it often doesn't work as expected because the spacing is not solely controlled by explicit \vspace commands. The environments themselves can introduce spacing, and this is where mdframed comes into the picture. mdframed is incredibly powerful for creating visually distinct boxes around content, but it also has its own set of default spacing parameters. These parameters, such as innertopmargin and innerbottommargin, control the space inside the frame, but the environment as a whole can still add vertical space outside the frame.

Secondly, the interaction between thmtools and mdframed is crucial here. thmtools is used to define theorem-like environments (like your example environment), and it provides a lot of flexibility in how these environments are styled and numbered. When you nest the example environment inside the examplebox environment (created by mdframed), you're essentially creating a layered structure. Each layer can contribute to the overall vertical spacing. The thmtools package might add space around the example environment itself, and mdframed adds space around the examplebox. This compounding effect is why simply reducing space with \vspace might not suffice. You need to address the spacing at each level of the environment nesting.

Finally, it's important to consider the order of operations. LaTeX processes the code sequentially, and the spacing introduced by each environment is added cumulatively. This means that the space added by thmtools for the example environment is added first, and then the space added by mdframed for the examplebox is added on top of that. To achieve zero spacing, you need to counteract the spacing introduced by both packages, and the order in which you do this can affect the outcome. So, what's the solution? Well, we need to dive into the specific parameters of both thmtools and mdframed to see how we can control this spacing. We'll look at how to adjust the margins and padding, and even explore some more advanced techniques to ensure those examples are as close as you want them to be. Stay tuned, we're getting there!

Solutions for Achieving 0mm Spacing

Okay, let's get down to brass tacks and figure out how to squish those examples together! We've identified that the problem stems from the default spacing introduced by LaTeX, thmtools, and mdframed. Now, we need to counteract that spacing. There are several strategies we can employ, and the best approach might depend on your specific needs and the overall design of your document. But don't worry, we'll walk through a few options to get you sorted. The key is to understand the parameters that control spacing in these environments and how to adjust them to your liking.

First, let's focus on adjusting the mdframed parameters. The mdframed package provides a plethora of options for customizing the appearance of your framed boxes, including the spacing around the content. We've already seen that you're using options like innertopmargin, innerbottommargin, innerleftmargin, and innerrightmargin to control the spacing inside the frame. This is a great start, but we also need to consider the spacing outside the frame. mdframed doesn't have explicit parameters for the outer margins in the same way it does for the inner margins. Instead, it relies on LaTeX's default vertical spacing mechanisms. This is where things get a bit trickier. To control the spacing outside the frame, we can use a combination of techniques, including adjusting the frametitleaboveskip and frametitlebelowskip parameters (if you're using a frame title) and directly manipulating the vertical space before and after the environment. However, for our goal of 0mm spacing, we need to go a bit further.

Next, let's consider modifying the spacing introduced by thmtools. The thmtools package provides a flexible way to define theorem-like environments, and it allows you to customize the spacing around these environments using the ewtheoremstyle command (though you're using \declaretheorem, which is a higher-level command that simplifies the process for common cases). By default, thmtools might add some vertical space before and after the theorem environment to separate it from the surrounding text. This is generally a good thing for readability, but it's precisely what we want to avoid in this case. To remove this spacing, we need to dive into the internals of thmtools and see how it defines the spacing. One approach is to define a custom theorem style that explicitly sets the spacing to zero. This involves using ewtheoremstyle and setting the spaceabove and spacebelow parameters to 0pt. Alternatively, we can try to counteract the spacing after the fact using negative vertical space, but this is often a less robust solution because it doesn't address the underlying cause of the spacing.

Finally, let's talk about a combined approach for achieving the desired result. The most reliable way to get those examples butted up against each other is to combine adjustments to both mdframed and thmtools. Here's a step-by-step strategy:

  1. Minimize inner margins in mdframed: Ensure that innertopmargin and innerbottommargin are set to the minimum reasonable value (you've already done this in your example).
  2. Address thmtools spacing: Define a custom theorem style (if needed) or find a way to globally reduce the spacing introduced by thmtools around your example environment. This might involve patching the example environment or using a different theorem style.
  3. Fine-tune with negative \vspace: If necessary, use a small negative \vspace command between the two examplebox environments to counteract any remaining spacing. This should be a last resort, used only to make minor adjustments.

By tackling the spacing at both the mdframed and thmtools levels, you'll have the best chance of achieving that elusive 0mm spacing. Remember, LaTeX is all about precision, and sometimes it takes a bit of tweaking to get things just right. Let's look at some code examples to see how this can be implemented.

Code Implementation: Achieving 0mm Spacing

Alright, let's put our knowledge into action and write some code that actually gets those examples glued together! We'll explore a couple of different approaches, focusing on modifying the thmtools spacing and making sure mdframed isn't adding any extra padding. Remember, the key is to be precise and address the spacing at its source. So, grab your LaTeX editor, and let's get coding!

First, let's look at modifying the thmtools spacing directly. As we discussed, thmtools might be adding some default vertical space around the example environment. To counteract this, we can define a custom theorem style that sets the spaceabove and spacebelow parameters to 0pt. This will effectively tell thmtools not to add any extra vertical space around the environment. Here's how you can do it:

\documentclass[11pt,a4paper]{article}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsthm}
\usepackage{thmtools}
\usepackage{mdframed}
\usepackage{lipsum}

\newtheoremstyle{nospacing}
  {0pt}      % spaceabove
  {0pt}      % spacebelow
  {\itshape} % bodyfont
  {}         % indent
  {\bfseries} % headfont
  {.}        % headpunct
  { }        % headsep
  {}

\declaretheorem[style=nospacing,name=Example]{example}

\newenvironment{examplebox}[1][]{%
\begin{mdframed}[backgroundcolor=blue!10, innertopmargin=0.3ex, innerbottommargin=0.3ex, innerleftmargin=0.6em, innerrightmargin=0.6em, #1]
}{\end{mdframed}}

\begin{document}

\lipsum[1]

\begin{examplebox}
  \begin{example}
    This is the first example.
  \end{example}
\end{examplebox}

\vspace{-0.5mm}

\begin{examplebox}
  \begin{example}
    This is the second example.
  \end{example}
\end{examplebox}

\lipsum[2]

\end{document}

In this code, we've defined a new theorem style called nospacing. This style sets both spaceabove and spacebelow to 0pt. We then use this style when declaring the example environment with \declaretheorem[style=nospacing,name=Example]{example}. This should eliminate the extra spacing introduced by thmtools. We've also included a tiny negative \vspace{-0.5mm} to compensate the space.

Next, let's consider adjusting the mdframed parameters more aggressively. While you've already set the inner margins, we can ensure that mdframed isn't adding any extra vertical space in other ways. One way to do this is to set the topline and bottomline options to false, which can sometimes reduce the default spacing. However, this might not be the best approach if you want the frame lines. Another option is to play with the innerleftmargin and innerrightmargin to see if reducing them further helps, but this will affect the spacing inside the frame.

Finally, let's look at a more robust solution that combines both approaches. Here's a complete code example that incorporates the custom theorem style and minimizes the mdframed spacing:

\documentclass[11pt,a4paper]{article}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsthm}
\usepackage{thmtools}
\usepackage{mdframed}
\usepackage{lipsum}

\newtheoremstyle{nospacing}
  {0pt}      % spaceabove
  {0pt}      % spacebelow
  {\itshape} % bodyfont
  {}         % indent
  {\bfseries} % headfont
  {.}        % headpunct
  { }        % headsep
  {}

\declaretheorem[style=nospacing,name=Example]{example}

\newenvironment{examplebox}[1][]{%
\begin{mdframed}[backgroundcolor=blue!10, innertopmargin=0.3ex, innerbottommargin=0.3ex, innerleftmargin=0.6em, innerrightmargin=0.6em, topline=false, bottomline=false, #1]
}{\end{mdframed}}

\begin{document}

\lipsum[1]

\begin{examplebox}
  \begin{example}
    This is the first example.
  \end{example}
\end{examplebox}

\vspace{-1mm}

\begin{examplebox}
  \begin{example}
    This is the second example.
  \end{example}
\end{examplebox}

\lipsum[2]

\end{document}

In this example, we've used the nospacing theorem style and set topline=false and bottomline=false in the mdframed environment. This combination should get you very close to 0mm spacing. If you still see a tiny gap, you can adjust the negative \vspace value slightly. Remember to compile the code with XeLaTeX to ensure everything renders correctly. With this approach, you should be able to achieve the desired 0mm spacing between your examples. LaTeX spacing can be a bit finicky, but with a bit of experimentation and these techniques, you'll be a spacing master in no time!

Final Tweaks and Considerations

So, you've implemented the code, and those examples are looking pretty snug! But, like any good craftsman, you want to make sure everything is perfect. LaTeX is all about the details, and sometimes a few final tweaks are needed to achieve the exact look you're going for. We've covered the main techniques for reducing vertical space, but let's delve into some additional considerations and potential pitfalls. These final touches can make the difference between a good-looking document and a truly polished one.

First, let's revisit the negative \vspace command. We've used this as a last resort to fine-tune the spacing, and it can be a handy tool. However, it's important to use it judiciously. Overusing negative \vspace can lead to inconsistent spacing throughout your document, and it can make your code harder to maintain. If you find yourself needing a large negative \vspace, it's a sign that there's likely a more fundamental issue with the spacing that needs to be addressed. Think of it as a band-aid solution – it works in a pinch, but it's not a long-term fix. A better approach is to identify the source of the extra spacing and eliminate it at its root.

Next, consider the overall visual balance of your document. While achieving 0mm spacing between those two examples might be your immediate goal, it's important to step back and look at the bigger picture. Does the tight spacing between the examples create a visual imbalance in the document? Does it make the examples feel cramped or cluttered? Sometimes, a little bit of whitespace can actually improve readability and make your document look more professional. This is where your aesthetic judgment comes into play. Experiment with slightly different spacing values and see what looks best in the context of the entire document. Remember, the goal is not just to minimize spacing, but to create a visually appealing and easy-to-read document.

Finally, let's talk about potential conflicts with other packages or environments. LaTeX is a powerful system, but it's also a complex one. Different packages can sometimes interact in unexpected ways, leading to spacing issues or other problems. If you're using a lot of custom environments or packages, it's possible that they're contributing to the vertical spacing problem. One way to diagnose this is to try removing packages one by one to see if the spacing changes. This can help you isolate the source of the conflict. Another approach is to consult the documentation for the packages you're using – they might have specific recommendations for dealing with spacing issues. If you encounter a particularly stubborn problem, don't hesitate to ask for help on a LaTeX forum or community. There are a lot of experienced LaTeX users out there who are happy to share their expertise.

By considering these final tweaks and potential issues, you can ensure that your document not only achieves the desired 0mm spacing but also maintains a consistent and professional appearance. LaTeX is a journey of continuous learning and refinement, and each document you create will help you hone your skills. So, keep experimenting, keep tweaking, and keep making those documents shine!

Conclusion: Mastering Vertical Spacing in LaTeX

Wow, we've really gone deep into the rabbit hole of vertical spacing in LaTeX! From understanding the default spacing mechanisms to tweaking thmtools and mdframed parameters, we've covered a lot of ground. You've learned how to diagnose spacing issues, implement code solutions, and even make those final aesthetic tweaks. Hopefully, you're now feeling much more confident in your ability to control vertical spacing in your documents. Remember, LaTeX is all about precision and control, and mastering spacing is a crucial skill for creating professional-looking documents.

We started by identifying the problem: unwanted vertical space between examples created using thmtools and mdframed. We explored the reasons why this happens, focusing on the default spacing introduced by LaTeX, thmtools, and mdframed. We then moved on to practical solutions, including modifying the thmtools theorem style, adjusting mdframed parameters, and using negative \vspace commands as a last resort. We even looked at some complete code examples to see how these techniques can be implemented in practice.

But the journey doesn't end here! LaTeX is a vast and powerful system, and there's always more to learn. The principles and techniques we've discussed in this article can be applied to a wide range of spacing issues in LaTeX. Whether you're working with theorem environments, lists, paragraphs, or any other element, the key is to understand the underlying mechanisms and how to control them.

So, what are the key takeaways from this deep dive into vertical spacing?

  • Understand the defaults: LaTeX has built-in spacing mechanisms that are designed to improve readability. These defaults are often helpful, but they can sometimes get in the way when you want precise control over spacing.
  • Identify the source: When you encounter a spacing issue, the first step is to identify the source of the extra space. Is it coming from thmtools, mdframed, LaTeX itself, or some other package or environment?
  • Address the root cause: Whenever possible, address the spacing issue at its root. This means modifying the parameters of the relevant environment or package, rather than relying on band-aid solutions like negative \vspace commands.
  • Experiment and iterate: LaTeX is a system that rewards experimentation. Don't be afraid to try different approaches and see what works best for your specific needs. And remember, it's often an iterative process – you might need to tweak your code multiple times to achieve the desired result.
  • Consider the overall balance: While precise spacing is important, it's also crucial to consider the overall visual balance of your document. Make sure that your spacing choices enhance readability and create a professional appearance.

With these principles in mind, you're well-equipped to tackle any vertical spacing challenge that comes your way. So, go forth and create beautiful, perfectly spaced documents! And remember, the LaTeX community is always there to help if you get stuck. Happy TeXing!