Editing and Evaluating Two-Dimensional Expressions

When you see a two-dimensional expression on the screen, you can edit it much as you would edit text. You can for example place your cursor somewhere and start typing. Or you can select a part of the expression, then remove it using the Delete key, or insert a new version by typing it in.

In addition to ordinary text editing features, there are some keys that you can use to move around in two-dimensional expressions.

Ctrl+.	select the next larger subexpression
Ctrl+Space	move to the right of the current structure
	move to the next character
	move to the previous character

Ways to move around in two-dimensional expressions.

	evaluate the whole current cell
Shift+Ctrl+Enter (Windows/Unix/Linux) or Cmd+Return (Mac OS X)
	evaluate only the selected subexpression

Ways to evaluate two-dimensional expressions.

In most computations, you will want to go from one step to the next by taking the whole expression that you have generated, and then evaluating it. But if for example you are trying to manipulate a single formula to put it into a particular form, you may instead find it more convenient to perform a sequence of operations separately on different parts of the expression.

You do this by selecting each part you want to operate on, then inserting the operation you want to perform, then using Shift+Ctrl+Enter for Windows/Unix/Linux or Cmd+Return for Mac OS X.

The Basic Commands ► y=x tab in the Basic Math Assistant, Classroom Assistant, and Writing Assistant palettes also provides a number of convenient operations which will transform in place any selected subexpression.