### 4. Mathematical Expressions

To make BSON books, there is no need to convert mathematical expressions into images which would increase file size dramatically. The BSON Books Viewer can display high quality mathematical expressions directly from MathML, LaTeX and AsciiMath. Among them, AsciiMath is the simplest to use. As an example, to display the following expression,

 int_0^1f(x)dx

you simply write the code:

You can try it yourself by modifying the code and click on "Convert". The syntax for AsciiMath is specified on this website.

Please note that this chapter has also demonstrated the capability to interact with users. Interactive contents are quite common for online Web applications, but the BSON Books Viewer can do it offline. The next chapter will show another example of interactive contents.