Nali commented on the post Office 2007 Math Editing/Display that it would be nice to have keyboard hot keys to switch between Professional and Linear format (build up/down), and between Display and Inline mode of equations. This is a great idea especially for those of us who like to use keyboards to speed up math entry. The present post mentions the main alt+= hot key for toggling math zones on and off and then considers other possible hot keys for math.

To insert a math zone at the insertion point, type alt+=. If the selection is nondegenerate (highlights one or more characters), alt+= toggles a math zone on and off. This hot key first shipped with Word 2007 and it also works in Office 2010 applications and Mac Word 2011 (type control+=, since the Mac doesn’t have an alt key). In some locales, the hot key may be different, but since most keyboards have an equal sign, alt+= is pretty general.

To maintain this international generality, we could use ctrl+alt+= to build a (Professional) math zone down to the linear format and shift+ctrl+alt+= to build a math zone up from the linear format. The alt+= hot key typically requires the use of both hands, so including ctrl and shift+ctrl is reasonably natural, especially if you’re a pianistJ.

It seems worthwhile to support Word’s standard subscript and superscript hot keys: ctrl+= and shift+ctrl+=, respectively. These hot keys toggle their respective states. For example, if you type some text, ctrl+=, and some more text, the latter will be subscripted up until you type ctrl+= again to go back on line. If you type one of these hot keys while some text is selected, that text’s script character will be toggled accordingly. In the linear format, subscripts and superscripts are usually entered with the _ and ^ operators as in [La]TeX or via the ribbon. But the standard hot keys can be handy too provided the scripts are not nested.

Word math zones are displayed inside an acetate enclosure that has a drop-down menu with Professional, Linear, Display/Inline, and Justification options. So you might wonder how Word converts from Display to Inline and vice versa. The essential feature is that if a math zone completely fills a hard or soft paragraph, it is shown in Display mode and is a display math zone. If one or more characters appear in the paragraph but not in the math zone, the math zone is displayed in Inline mode and is an inline math zone. To convert a display math zone to an inline math zone, Word inserts a space directly following the math zone. To convert an inline math zone to a display math zone, Word deletes the space for the previous case. More generally, Word inserts a carriage return before and/or after the math zone, depending on how much is needed to obtain a math zone that completely fills its paragraph.

It’s pretty easy to convert between inline and display modes on the keyboard using the space bar and the enter key as necessary. So maybe we don’t need a hot key for it. But if we do, shift+alt+= is currently undefined. Using that along with the others above would define all combinations of ctrl, shift, alt and = that don’t distinguish between left and right control/shift/alt keys. The fact that they all involve the equal sign suggests they are math hot keys and makes them easier to remember.

Other hot keys that are handy in math zones include the home/end and arrow keys. In some applications, the [shift+]tab moves between elements in a matrix. The [shift+]tab key is also used to change the indentation of manual line breaks. In my old PS Technical Word Processor, hot keys were used to enter Greek and math symbols. For example, alt+a inserted α. But TeX’s symbol notation is generally so easy to use, it doesn’t seem necessary to have hot keys for symbols. If you use α a lot, you might want to add the autocorrect entry \a for α, which is certainly faster than typing \alpha. Hopefully at some point, I’ll add autocomplete to the math autocorrect facility and then the difference between typing \a and \alpha will be even smaller.

alt+x is another useful hot key that toggles between a character and its Unicode hexadecimal value. In fact, I entered the α’s here by typing 3b1 alt+x. Admittedly to use this approach, you have to be a bit of a Unicode geek.