Evaluation Area of a Block

  A block also contains an area, located just below the edit area, in which evaluation information is displayed. When the user evaluates or steps through the expression in the edit area, the (possibly incomplete) answer appears here. Editing the expression in the Edit Area erases the Evaluation Area and loses any state.

By clicking the left mouse button on the expression in the Evaluation area, one may highlight one of its subexpressions. This subexpression is now selected . Clicking on it again unselects it.