Customizing Editing Behavior

The General Editing Preferences dialog allows you to customize a variety of editing behaviors.

Pressing spacebar will insert

You can choose what gets inserted when pressing the spacebar, modifying the default behavior. Your choices are to insert an Invisible times after an operand, space otherwise, an Invisible times always, a Space always or Nothing. The most convenient spacebar behavior depends on whether accurately encoding the underlying mathematical meaning of an expression is important in a particular context.

In many situations, the underlying mathematical meaning is not as important as the visual appearance of an expression. In these contexts, most users prefer the spacebar simply insert space characters, as on a typewriter. However, MathML rendering engines employ standard mathematical typesetting rules to automatically add space around operators and other constructs. Inserting additional space characters in markup generally produces worse-looking results unless there is a specific reason. Regardless, touch-typists often find themselves hitting the spacebar out of habit. As a result, users may want to turn the spacebar off entirely.

In contexts, the mathematical meaning of an expression is important, such as material intended for symbolic computation, automatic answer checking, etc. In these situations, extraneous space characters may cause trouble. Moreover, in these contexts, adding invisible "hint characters" to resolve ambiguous situations is important. The most common situation where ambiguity arises is determining whether adjacent constructs should be multiplied or whether they represent a function application (e.g., does m(x + y) mean "m times x plus y" or "m of x plus y"). The convention in MathML is to resolve the ambiguity by marking the multiplications with an Invisible Times character. Thus, users creating semantically meaningful MathML generally prefer to have the space bar insert the Invisible Times character. The option to have the spacebar insert an Invisible Times character only after an operand is a convenient compromise that allows one to space normally within text tokens without modifying the overall editing behavior.

Show Ruler

Check this box to show a ruler above the text area. The drop-down menu to the right of this option allows you to choose the units displayed in the ruler.

Make "fence" characters non-stretchy by default

Check this box to make inserted parentheses and other "fence" characters not stretch by default. In MathML, fence characters marked as non-stretchy will remain their default size (i.e., not growing automatically to cover the height of other content within the same parent element). In order for fences to grow to the expected height in many contexts, the conscious insertion of additional expression groups to collect fences and surrounding content is required. While this is good practice and results in semantically meaningful markup, many users prefer to instead turn off automatic stretching for fences.

Make single characters italic by default

Single characters will be inserted in italic if this box is checked, and as upright text if not. Since single character identifiers are traditionally typeset in italics in mathematics, this option is primarily useful when entering chemical equations where single character identifiers are traditionally typeset in an upright style.

Make uppercase Greek letters normal by default

Uppercase Greek letters will be inserted as normal if checked (i.e., upright, not italicized) or italic if not checked.

Recognize Common Functions

Check this box to turn on automatic recognition of functions. When this option is not selected, you must manually control how characters are wrapped in MathML token elements. See Recognize Common Functions for details.

Render differential d in double struck

Differential d will appear as a double struck character to differentiate it from a regular character d. This also affects the exponential e, imaginary i, and imaginary j.

Non-MathML Elements

For an explanation of non-MathML elements and safe mode, see Non-MathML Elements.

The following options for safe mode are explained below:

Enable None - This indicates that none of the non-MathML elements should be shown, and that no warnings will be issued upon deletion of non-MathML elements. Checking this will automatically uncheck the Enable all, Processing instructions, Comments, and Non-MathML tags checkboxes.

Enable All - This indicates that all of the non-MathML elements should be shown, and that warnings will be issued upon deletion of all types of non-MathML elements. Checking this will automatically uncheck the Enable none checkbox and enable the Processing instructions, Comments, and Non-MathML tags checkboxes.

Processing instructions - If checked, processing instructions will be displayed in the user interface in Design View, and attempts to delete a processing instruction may be blocked or a warning will occur when these elements are deleted. If not checked, processing instructions will not be displayed, and no errors will occur upon deletion of them.

Comments - If checked, comments will be displayed in the user interface in Design View, and attempts to delete a comment may be blocked or a warning will occur when these elements are deleted. If not checked, comments will not be displayed, and no errors will occur upon deletion of them.

Non-MathML tags - If checked, non-MathML tags and data will be displayed in the user interface in Design View, and attempts to delete non-MathML tags and data may be blocked or a warning will occur when these elements are deleted. If not checked, non-MathML tags and data will not be displayed, and no errors will occur upon deletion of them.

Note that the "Enable all" option is automatically checked if all three of the non-MathML type boxes are enabled, and the "Enable none" option is automatically checked if none of the type boxes are enabled. This is done to keep the user interface consistent.

Display non-MathML element warning - This checkbox indicates if a warning dialog should appear when an equation contains non-MathML elements. If these elements are present and this is option is enabled, the dialog will appear when the the user switches from Source View to Design View, when the user pastes an equation containing non-MathML elements, or when the equation editor window opens an equation with non-MathML elements.