Initial Query

In latex when I force a newline in a caption with \\ it gives an error saying \Hy@tempa has an extra } runaway argument?

LLM Generation

Query

In latex when I force a newline in a caption with \\ it gives an error saying \Hy@tempa has an extra } runaway argument?

Output

The error "Runaway argument?" involving `\Hy@tempa` usually arises when you use verbatim commands (like `\verb`) or fragile commands (like `\\`) inside moving arguments, such as section titles, captions, or index entries. Captions are particularly prone to this. Here's why and how to fix it: * **Why it happens:** LaTeX's internal mechanisms for handling these moving arguments sometimes struggle with special characters and commands. The `\\` is considered fragile because its meaning can change depending on the context. * **How to fix it:** Protect the fragile command `\\` by enclosing it in a `\protect` command:

   \caption{This is the first line of the caption. \protect\\ This is the second line.}
   

Alternatively, for captions specifically, you can use the `caption` package and its `\caption` command, which handles line breaks more robustly:

   \usepackage{caption}

   \caption[Short caption for list of figures]{This is the first line of the caption. \\ This is the second line.}

The optional argument `[Short caption for list of figures]` provides a shortened caption for the list of figures, while the main argument is the full caption displayed below the figure. Using the `caption` package often simplifies caption formatting and handles many potential issues automatically. * **Other potential causes (less common but worth checking):** * **Missing closing brace:** Double-check that all your curly braces `{}` are balanced within the caption. A missing `}` can sometimes lead to cascading errors that manifest as a runaway argument. * **Conflicting packages:** In rare cases, a conflict between packages might contribute. If the problem persists after trying the above solutions, try minimally reproducing the error in a small document with only the essential packages loaded to see if you can isolate the conflict. * **Verbatim inside caption:** If you're using `\verb` inside a caption, that's almost guaranteed to cause problems. You'll need to find a different way to represent the verbatim text, perhaps using a `lstlisting` environment (from the `listings` package) if it's code, or a `verbatimbox` (from the `verbatimbox` package). **Example:**

\documentclass{article}
\usepackage{graphicx}
\usepackage{caption} % Recommended

\begin{document}

\begin{figure}
    \centering
    \includegraphics{placeholder.png} % Replace with your image
    \caption{This is the first line. \protect\\  This is the second line (using \texttt{\textbackslash protect}).}
\end{figure}

\begin{figure}
    \centering
    \includegraphics{placeholder.png} % Replace with your image
    \caption{This is the first line. \\ This is the second line (using the \texttt{caption} package).}
\end{figure}


\end{document}

By using `\protect` or the `caption` package, you should be able to resolve the "Runaway argument?" error and have proper line breaks in your captions. The `caption` package is generally the preferred solution for its robustness and additional features.

Substring Evaluation

Testing if the previous output contains the string \protect: True

Initial Query

In latex when I force a newline in a caption with \\ it gives an error saying \Hy@tempa has an extra } runaway argument?

LLM Generation

Query

In latex when I force a newline in a caption with \\ it gives an error saying \Hy@tempa has an extra } runaway argument?

Output

The error "Runaway argument?" involving `\Hy@tempa` usually arises when you use verbatim commands or environments (like `\verb` or `verbatim`) inside a moving argument like a section title, caption, or floating environment. Captions are considered moving arguments because LaTeX might have to rearrange them for optimal typesetting. Here's why and how to fix it: **Why it happens:** The `\\` command within a `\caption` can conflict with the internal mechanisms LaTeX uses for hyperlinks and cross-referencing, especially if you're using the `hyperref` package. `\Hy@tempa` is a macro used by `hyperref`, and verbatim content interferes with its parsing. **Solutions:** 1. **`\protect\\`:** The most common and straightforward solution is to protect the newline command with `\protect`. This prevents `\\` from being expanded prematurely:

   \caption{This is the first line.\protect\\ This is the second line.}
   

2. **`\newline`:** Instead of `\\`, try using `\newline`:

   \caption{This is the first line.\newline This is the second line.}
   

3. **`caption` package:** The `caption` package provides more control over caption formatting and often handles line breaks more robustly. If you're not already using it, consider adding `\usepackage{caption}` to your preamble. Then you can use `\\` directly or the `caption` package's commands for better control:

   \usepackage{caption}
   ...
   \caption[Short caption]{This is the first line.\\ This is the second line.}
   

4. **Parboxes:** For more complex formatting within a caption, consider using a `minipage` or `\parbox`:

   \caption{This is some text.
   \parbox{.9\linewidth}{This is a longer part of the caption that can be broken across multiple lines without any issues related to verbatim content or hyperref.}}
   

Adjust the width (`.9\linewidth` in this example) as needed. 5. **Check for Verbatim in Caption:** Double-check that you're not unintentionally using verbatim commands (like `\verb`) directly within the caption. If you need to display code within a caption, enclose it in a `verbatim` environment *within* a `minipage` or `\parbox`. **Example showing the error and the fix:**

\documentclass{article}
\usepackage{graphicx}
\usepackage{hyperref}  % Often the source of the conflict

\begin{document}

\begin{figure}
  \centering
  \includegraphics{example-image}
  \caption{First line \\ Second line} % This will likely cause the error
\end{figure}

\begin{figure}
  \centering
  \includegraphics{example-image}
  \caption{First line \protect\\ Second line} % This is the corrected version
\end{figure}

\end{document}

By using one of these methods, particularly `\protect\\` or the `caption` package, you should be able to resolve the "Runaway argument?" error related to `\Hy@tempa` and have proper line breaks in your captions.

Substring Evaluation

Testing if the previous output contains the string \protect: True

Initial Query

In latex when I force a newline in a caption with \\ it gives an error saying \Hy@tempa has an extra } runaway argument?

LLM Generation

Query

In latex when I force a newline in a caption with \\ it gives an error saying \Hy@tempa has an extra } runaway argument?

Output

The error "Runaway argument?" involving `\Hy@tempa` usually arises when you try to use verbatim text or certain fragile commands within moving arguments like section titles, captions, or table of contents entries. `\\` is one such command that can be problematic. Here's how to fix it and achieve line breaks in captions: 1. **Using `\protect\\`:** The most straightforward solution is to protect the `\\` command by prefixing it with `\protect`. This prevents it from being expanded too early.

   \caption{This is the first line.\protect\\ This is the second line.}
   

2. **Using the `caption` package:** The `caption` package provides more robust caption handling and simplifies line breaks. It's generally recommended for better control over caption formatting.

   \usepackage{caption}

   \caption[Short caption for list of figures]{This is the first line. \\ This is the second line.} % Short caption optional

3. **Using a `parbox` (for more complex formatting):** If you need finer control over line breaks and alignment within the caption, you can use a `\parbox`.

   \caption{This is a longer caption that requires more formatting. \parbox{0.8\textwidth}{This is the first line of the inner parbox.\\ This is the second line, and it can be quite long without affecting the overall layout of the caption.}}
   

Adjust the width (`0.8\textwidth` in this example) as needed. 4. **Using `\newline` (less common):** While `\newline` can sometimes work, `\protect\\` or the `caption` package are generally preferred for better consistency. **Example demonstrating the `caption` package:**

\documentclass{article}
\usepackage{caption}

\begin{document}

\begin{figure}
    \centering
    % Include your figure content here
    \caption{This is the first line of the caption.\\ This is the second line, and it can be quite long.}
    \label{fig:my_figure}
\end{figure}

\end{document}

**Why does this error occur?** LaTeX handles certain commands differently depending on the context. Commands like `\\` are considered "fragile" and need protection when used within "moving arguments" (parts of the document that might be processed multiple times or moved around during typesetting, such as captions). Without `\protect`, the command is expanded prematurely, leading to the `\Hy@tempa` error. The `caption` package handles these fragile commands internally, so you don't need to worry about protecting them. By using these methods, you can safely include line breaks in your captions without encountering the "Runaway argument?" error. The `caption` package is highly recommended for its improved caption formatting capabilities.

Substring Evaluation

Testing if the previous output contains the string \protect: True

Initial Query

In latex when I force a newline in a caption with \\ it gives an error saying \Hy@tempa has an extra } runaway argument?

LLM Generation

Query

In latex when I force a newline in a caption with \\ it gives an error saying \Hy@tempa has an extra } runaway argument?

Output

The error "Runaway argument?" involving `\Hy@tempa` almost always points to issues with fragile commands within moving arguments, like section titles, captions, or table of contents entries. The `\\` command is fragile, meaning its definition can break when moved around by LaTeX's internal processes. Here's how to fix it and why it happens: **The Solution: Protect the `\\`** You need to make `\\` robust (protected) within the caption. The easiest way is to use `\protect\\`:

\caption{This is the first line of my caption.\protect\\ This is the second line.}

**Explanation:** * **Fragile Commands:** Commands like `\\`, `\ref`, `\cite`, and others are considered "fragile." When LaTeX processes moving arguments (like captions that go into the list of figures), it might need to expand and manipulate the argument's content before placing it in its final location. During this process, the fragile commands can get misinterpreted, leading to the "Runaway argument?" error. * **`\protect`:** The `\protect` command tells LaTeX to treat the following command as robust within a moving argument. It essentially prevents the command from being expanded prematurely, ensuring it's interpreted correctly in its final context. **Example:**

\documentclass{article}
\usepackage{graphicx}

\begin{document}

\begin{figure}
    \centering
    \includegraphics{example-image}  % Replace with your image
    \caption{This is a caption with a forced line break.\protect\\  Here is the second line.}
\end{figure}

\end{document}

**Alternative using `caption` package:** The `caption` package provides more control over caption formatting and often handles line breaks more gracefully. If you're using this package, you might not need `\protect`. However, it's still good practice, especially for complex captions:

\documentclass{article}
\usepackage{graphicx}
\usepackage{caption}

\begin{document}

\begin{figure}
    \centering
    \includegraphics{example-image}
    \caption[Short caption for List of Figures]{This is a caption with a forced line break.\protect\\ Here is the second line.} % Short caption optional
\end{figure}

\end{document}

By using `\protect\\`, you ensure that your line breaks in captions are handled correctly, avoiding the "Runaway argument?" error. It's a good habit to use `\protect` with fragile commands in moving arguments as a preventive measure.

Substring Evaluation

Testing if the previous output contains the string \protect: True

Initial Query

In latex when I force a newline in a caption with \\ it gives an error saying \Hy@tempa has an extra } runaway argument?

LLM Generation

Query

In latex when I force a newline in a caption with \\ it gives an error saying \Hy@tempa has an extra } runaway argument?

Output

The error "Runaway argument?" involving `\Hy@tempa` within a caption almost always arises because you're using verbatim text or a command that's not allowed inside a moving argument (like a caption). Captions are implemented using a command that internally moves the caption to the appropriate location (above or below the figure/table). Certain commands don't work within these moving arguments. Here's how to fix it and the underlying reasons: **1. Protected `\\`** The most common solution is to use `\\protect` instead of just `\\` inside the caption. This prevents `\\` from being expanded too early, which is often the cause of the "Runaway argument" error.

\caption{This is the first line.\\protect This is the second line.}

**2. `caption` package and its options** The `caption` package provides greater control over captions and often resolves these issues. If you're not already using it, include it in your preamble:

\usepackage{caption}

You can then use the `format` option for finer control. For example:

\captionsetup{format=plain} % Allows standard \\

Other useful `format` options include `hang` (for indented second and subsequent lines) and `listing` (for verbatim-like captions, though still with some limitations). **3. `\newline` instead of `\\`** In some cases, using `\newline` instead of `\\` might work within a caption, but this isn't universally guaranteed and might produce slightly different vertical spacing. **4. Verbatim environments inside captions (generally avoid)** Avoid using verbatim environments (like `verbatim` or `lstlisting`) directly inside captions. If you absolutely must include verbatim text, use a `\verb` command but be mindful of special characters like `%` and `#` which need to be escaped:

\caption{The command is \verb|\texttt{example}|.}

**5. Other problematic commands** Certain other commands, particularly those that affect formatting or involve fragile commands, might also cause this error within a caption. If you encounter this, try protecting them with `\protect` or consider rephrasing the caption to avoid their use. **Example demonstrating the fix:**

\documentclass{article}
\usepackage{caption}

\begin{document}

\begin{figure}
  \centering
  % Some figure content
  \caption{This is the first line.\\protect This is the second line.} % Correct usage
  %\caption{This is the first line.\\ This is the second line.} % Incorrect - will likely cause an error
\end{figure}

\end{document}

By using `\\protect`, or the `caption` package with appropriate options, you should be able to resolve the "Runaway argument?" error and have multi-line captions without problems. If you're still facing issues, please provide a minimal working example (MWE) that reproduces the error, and I can assist further.

Substring Evaluation

Testing if the previous output contains the string \protect: True