Call stack
Variables
Press Run to see the program here.
Run is the rocket in the toolbar. F5 or Ctrl+Enter runs it too,
and F1 shows help for the command at the cursor.
Click the margin beside a line, or press F9, to stop there and see the variables.
Turn on Live, beside Run, to see your changes here as you type. Hold Alt and drag a number
to change it, or click a colour's swatch.