You continue editing the buffer. Finally, you make the following text in the Emas buffer.

You can download the actual file

binomial.txt.

__Re-editing the Maxima command__

In
some cases you may get something different from what you expected. This
is often the case due to the processing error in Maxima. In such a
case, you remove the errnous image (often a plain square image) and
restore the original Maxima command for correcting typing errors. You
can move the cursor right after the errnous image. Then type:

C-c &

and the Maxima command text is restored. You can edit the command text, then type:

C-c !

again and Maxima starts processing the new command text. You can repeat this cycle to get the correct output image.

__Viewing and editing the LaTeX command generated by Maxima__

When
processing the Maxima command, Maxima computes the command then the
result is converted to LaTeX command and concatenated to the Maxima
command with "&" character. So, after you convert the Maxima
command to an image, you can see both the Maxima command and the LaTeX
command by typing:

C-u C-c &

Here is a result of typing above keys when cursor is placed just after the formula in the theorem:

{maxima binomial(n-1,i-1)+binomial(n-1,i)=binomial(n,i) maxima}&{latex {n-1\choose i}+{n-1\choose i-1}={n\choose i} latex}

You
may be surprised that you can delete the Maxima command and the
character "&", keeping only the LaTeX command. Still, if you move
the cursor right after the LaTeX command and type:

C-c !

you will see the same formula image as you obtained previously.

Placing the cursor just after the image and type:

C-c &

and
you see the LaTeX command again. Now if you are knowledgable about
LaTeX, you can edit the LaTeX command and convert it to the image again.

*Continues to ***Tutorial of imath 3**
...