LisaCalc: New vs. Used Rows and Columns

On a new Calc sheet, enter the following:

in cell A1 enter 20
in cell A3 enter 30
in cell A4 enter 50
in cell A5 enter 100
in cell A6 enter MIN(A1:A5)

The value will be 20.

Now, enter anything into any cell (other than A2) in row 2. The value
in A6 changes to 0. The problem is that that LisaCalc makes a
distinction between new and used rows or columns. To get around this,
cut row 2 and insert another in its place.