Using Strikethrough in LaTeX

There are two cases, math mode, and not math mode. Outside of math mode the package to use is

  \usepackage[normalem]{ulem} %%use outside math mode
  \usepackage{cancel}         %%use insdide math made

  \sout{text you want to strike out}  %%not math mode
  \cancel{math text to strike out goes here}  %%math mode

Synctex in TeXworks fails when spaces are in filenames

In TeXworks under Edit -> Preferences -> Typesetting click pdfLaTeX+MakeIndex+BibtTeX and select "Edit". The program should read "texify.exe" for arguments you may have

 --pdf
 --tex-option=--synctex=-1 (or perhaps 1)
 $fullname

The synctex command allows you to jump back and forth between the source code and the output pdf file ("source specials"). However, I discovered that this does not work if you have spaces in the path of your .tex file. I believe the only difference between the -1 and the 1 above is that -1 means uncompressed synctex file and 1 means compressed (gzipped).

Action arrows in LaTeX using tikz

A nice action arrow in text is

 \usepackage{tikz}
 ...
 \def\acts{ 
  \hspace{.1cm} { 
  \begin{tikzpicture}
   \draw[->] (0,0) arc (315:45:1.2mm); 
  \end{tikzpicture} 
  \hspace{.1cm} 
  }
 }

Inside a commutative diagram, you can define an arrow from a point to itself in the following way

 \begin{tikzpicture}
  \fill (0,0) circle (2pt); %just draw a dot 
  \draw[->] (0,0) to [out=135,in=45,min distance=1cm] (0,0); 
 \end{tikzpicture}