It takes time to figure out how $\LaTeX$ works. However, the process of learning $\LaTeX$ really forces you to understand mathematical notation. I just sent you an email with some tips after your post. I just thought of two things that I forgot to mention in that email. First, if you want to obtain an exponent with more than one character, you should enclose the exponent in braces. For example, to obtain $a^{-1}$ you should type

Second, to make the summaries easy to read, they should all have the same format. If you look at the sidebar on the right side of the page, I tell you exactly how to format your entry. Here's how you should do yours (and everyone else should do theirs):

**Group**
- A group $(G,\circ)$ is a set $G$$ together with a binary operation…blah blah such that

1. associative…

2. identity…

3. inverses…

which is typeset using

```
: **Group** : A group [[$(G,\circ)$]] is a set [[$G$$]] together with a binary operation...blah blah such that _
1. associative... _
2. identity... _
3. inverses...
```

As I've mentioned before the colons really are supposed to be there. Also, the totally not obvious thing is the use of the underscore _ to carry the next line inside the definition block. There needs to be a space to the left of the _.