# Getting Started with the WebEQ Input Control

The WebEQ Input Control is an equation editor applet. It is
based on the idea of an *equation template*. There are templates
for fractions, subscripts, superscripts, matrices, etc. To
build an equation, insert templates, and then fill in the
blanks.

To fill in the blanks in templates, enter letters and numbers from
the keyboard, select symbols from a pulldown palette on the toolbar.
You can also fill in a blank with another template.

By nesting equation templates inside one another, you can build up
almost any equation. Navigate around an equation using the mouse and
arrow keys. Cut and paste subexpressions to edit even very complex
expressions.

All of the templates and symbols are directly based on MathML. See
the WebEQ documentation for more information about MathML.

## Moving the Cursor

The WebEQ Input Control tries to make cursor movement as natural and
as intuitive as possible. In general, the left, right, up and down
arrows move the cursor to the next valid insertion point in the
corresponding direction. Similarly, clicking the mouse anywhere in an
equation moves the cursor to the closest valid location to the click.

Behind the scenes, the WebEQ Input Control is negotiating a
complicated nested structure of MathML templates. Moving the cursor
one position to the right on the screen can involve jumping in and out
of MathML structures.

The cursor may occasionally not move exactly as you would expect on
account of the nesting of the MathML structure. In these cases, the
cursor movement is giving you additional information about the
structure of your equation.

Watch the gray box attached to the cursor. The gray box indicates
the current template in which the cursor is located. Usually,
unexpected cursor motion is the result of moving in and out of
templates.

## Entering Symbols

To enter a symbol in an equation, click on it on the toolbar, or
select it from one of the symbol palettes, also on the toolbar.