A descriptive text in a cell that is not used for any calculations.
A string in a cell which evaluates to a (floating point) numeric result. The simplest expression is a number; more complicated expressions can be entered in Scheme syntax.

The Scheme used in Siag has a few extensions to make it more useful in a spreadsheet. These new functions have been added:

The area where labels and expressions are displayed.
The grey area where column numbers are displayed.
The grey area where row numbers are displayed.
The "other" standard position in the document, which is used for commands which need two coordinates.
point or current cell
The cell where labels and expressions are entered. The current cell can be moved using arrow keys, the mouse and other methods.
The block is a rectangular area which is displayed in inverse. It is used for commands which operate on a whole range of cells.

Ulric Eriksson - January 1997 -