Using formulas in conditional formatting in Apple Numbers

After research and trial & error sessions, I understood that using formulation in conditional formatting rules is impossible in Numbers. One can only use simple comparisons for formatting. Preparation of values for comparison is needed to be done on the table.

I had the same issue with Numbers 5.0. I wanted to highlight a cell if it wasn't a consecutive number based on the cell above, eg. to highlight a gap. I found that I had to add a column with the formula eg $B1 = $A1 + 1, then highlight column A and add the condition rule for $A2 not equal $B1 then highlight.

This then set the rule for all cells in col A, and adjusted the target of the comparison. I then hid column B.