This module explains how to open the Math Editor, create math, edit existing math, and keyboard shortcuts. There is also a separate tutorial page with examples showcasing the features.

At the end of this module are nuances and limitations of the editor. Please, let us know which ones you'd really like to see incorporated!

When editing a Module using using Mozilla's Firefox browser, click on a part of the module to open a blue editing box. On the top-right hand side of the box is a "MathML Editor" link which will open up the editor.

Figure 1: Begin editing and in the top-right corner is a MathML Editor link

Figure 2: Once clicked, a popup window will appear containing the Math Editor

The popup window can remain open while editing a module and can even stay open while editing several modules. At any point one can close the window, but the contents of the editor will be lost.

The Editor has 4 main sections, detailed below. The toolbar provides a way to insert new operations, a navigation tree to show where the cursor is located, and standard buttons for undo, preview, and source editing.

The main editing area is located below the toolbar and contains the math that is being edited.

The toolbar contains a row of buttons representing categories of different mathematical operations. These are enabled when something is selected in the editing area. Note: The editor does not infer multiplication and addition. See Nuances for how to insert next to existing math by wrapping existing math. Explain the different sections, when it's enabled, how things get inserted, and Keyboard Entry for things.

Menu

Clicking a category in the top row of the toolbar will open a menu of mathematical operations to insert. To the right of each operation is a name that can be entered from the keyboard at the cursor position in the main editing area. For example, instead of using the toolbar to enter the symbol for pi, the user could enter "pi" or "<pi/>" (the MathML version of pi) in the cursor and press the Enter key.

Path

Shows the path to the cursor location. Math is organized in a tree-like hierarchy (see Navigating Math) and the path represents where in the tree the cursor currently is. The path (and context) are important because they define what can be inserted and where it will go.

Undo/Redo

These buttons allow the user to undo an operation such as deletion or insertion. See Keyboard Shortcuts for details on using these features from just the keyboard.

Preview

Shows what math will look like when module is published. To resume editing, one must click the Preview button a second time.

View Source

Math in Connexions is represented in an XML format known as MathML. Clicking the View Source button will allow editing of the raw MathML.

This is the main area for creating math. It begins empty, but math can be pasted directly in here from Connextions. The tutorials contain instructions on moving math from Connexions to the math editor and back. The editing area is the most important part of the editor and as several subsections, outlined below:

Math in the editor is structured like a tree. It can be thought of as removing the precedence rules and just having parentheses. For example, the formula "a*x^2+b*x+c=0" which is displayed (using the editor) as a⁢x2+b⁢x+c=0 a x 2 b x c 0 and as a tree would look like Figure 3. The equal sign has the least precedence and so is on the top. Similarly, xx binds tighter to 22 through the power operation than to aa through the times operation.

Figure 3: a⁢x2+b⁢x+c=0 a x 2 b x c 0 as a tree

Color notation (legend)

_ f _ = x 1 if x < 0 x 2 if __ > 0 __ otherwise _ f _ = x 1 if x < 0 x 2 if __ > 0 __ otherwise

There are two subsets of the MathML language; Content MathML and Presentation MathML. Content, as the name implies, focuses on expressing operations like addition, integration, matrices, etc. Presentation focuses on how precisely math is displayed and contains elements like tables and subscripts.

Figure 4: Content MathML typically has fewer places to enter information and navigation is simpler, and Presentation MathML allows the user to tweak the way formulas are presented and is used by OCR and import software.

Comparing Content and Presentation MathML
Content MathML (a) Presentation MathML (b)

The editor supports creating and editing the Content Math subset while being able to navigate through Presentation MathML. Every thing that is entered into the Editor is entered as Content Math. For example, entering a*x^2+b*x+c=0 will be translated as the variable aa times xx to the power of 22 and added to bb times xx ...

The Math Editor can be used entirely from the keyboard (See Keyboard Input). The cursor can be in one of four places. Either it is editing a variable or number, editing an empty block of text, next to a complicated expression, or has selected an expression. In each of these places there are several things that can be done.

Editing a variable, number, or block

At this point, the cursor is surrounded by a blue box and the user can type in expressions or even paste existing MathML. The expression will be parsed as soon as the cursor leaves the box or presses the Enter key (in the case of an expression) or immediately when MathML is pasted in. The user can leave the box by pressing clicking on the toolbar or by pressing the Left, Right, or Tab key. See Keyboard Input for more on expressions.

Next to a Complicated Expression

When a cursor is next to a complicated expression, the expression is shown with a light gray background (See Context). From this point, one of three things may be done. The user may add on to the expression. This is done by just typing. For example, if the cursor is to the left of (−π)⁢i , the user may type -1=e^ and parse the expression to yield −1=e(−π)⁢i 1 e

One can select the expression by either pressing Shift+Right/Left (depending on whether the cursor is before or after the element), Delete, or Backspace key. See Selection for what can be done next.

Instead of using parentheses to denote which operations are grouped, the math editor highlights the current context for the operation. The context shows the position of the cursor relative to existing math in the editing area and is displayed using a gray background. An example of a confusing position can be shown using the following example. Suppose the editor contains the term a+b⁢c a b c and the cursor is just after the cc. If the user enters "^2" it is not clear what should be squared. At that position the user may want to square cc, b⁢c b c , or the entire term a+b⁢c a b c . This produces very different math, namely a+b⁢c2 a b c 2 , a+b⁢c2 a b c 2 , and a+b⁢c2 a b c 2 . In the above example, the context would highlight precisely the math that ended up being in parentheses. One can think of the context as defining where the parentheses should go once the new math is entered.

There are several places the user can enter text into the editor. Most of them behave the same way, but listed below are common uses and specifics:

Categories

There are three categories of key presses and are enumerated in the table below.

This is a text entry place. See shortcuts. can paste MathML (Ctrl+V from Mathematica, MathType, etc), or enter simple algebra (see Shortcuts). Moving away using Enter, Tab, Left, Right will cause the input to be parsed and converted into Math.

Blocks are holes that may need to be filled. (Click or Tab to them). Required blocks have a yellow background and optional ones are transparent and have a dotted border.

There are several nuances in the editor, and common ones are listed here, along with workarounds. Also listed are limitations of the editor and things we'd like to get working soon.