Math & Science ⇒ \dot{vec{v}} formatting.

[utesfan100]

I am having difficulties formatting a series of equations of the form listed below. I am using TeXnicCenter on a Windows 7 system.

I have distilled the issue I am having down to the following code fragment.

Code: Select all

\documentclass[12pt,leqno]{book}

%\usepackage{amsmath}         % LINE A
                                      
\title{Dot Vector Test}
\begin{document}
%\begin{subequations}
\begin{equation}
\dot{\left(a\vec{b}c\right)}  % LINE B
\end{equation}
%\end{subequations}           % LINE C
\end{document}

As written this code formats correctly, but does not have subequation numbering I desire.

Removing the comments in front of lines A, B and C properly handles sub-numbering, but then formats incorrectly, with the b dislocated to the far right of the entire \dot fragment, as shown here:

The erroneous formatting

Error.gif (1.51 KiB) Viewed 2913 times

Removing the comments in front of lines B and C indicates subequations is not recognized.

I am new to TeX, and any help on this issue would be appreciated.

[frabjous]

Seems like a bug in amsmath to me. Not sure what do about it other than kludge your way around it. Here's one possible kludge:

Code: Select all

\documentclass[12pt,leqno]{book}
\usepackage{amsmath}         % LINE A
\newsavebox{\innerdotpart}
\savebox{\innerdotpart}{$\left(a\vec{b}c\right)$}
          
\title{Dot Vector Test}
\begin{document}
\begin{subequations}
\begin{equation}
\dot{\usebox{\innerdotpart}}
\end{equation}
\end{subequations}  
\end{document}

[utesfan100]

Thank you! That kludge works!

The following change works too, allowing the save box to be a much smaller and more likely to be used again portion of this issue.

Code: Select all

\documentclass[12pt,leqno]{book}

\usepackage{amsmath} 
\newsavebox{\vecb}
\savebox{\vecb}{$\vec{b}$}
                                      
\title{Dot Vector Test} 
\begin{document}
\begin{subequations}
\begin{equation}
\dot{\left(a\usebox{\vecb}c\right)}
\end{equation}
\end{subequations}
\end{document}

[localghost]

Now that the problem is solved, please be so kind and mark the topic (not the last post) accordingly as clearly written in the Board Rules (to be read before posting). Please keep that in mind for the future so that further reminders will not be necessary.


Best regards and welcome to the board
Thorsten

[utesfan100]

Fixed, and my apologies for originally failing to follow the icon customs of the forum.

The AMS technical support staff verified this is a bug. Are there maintained compilations of known bugs in the standard packages?