I am trying to apply a conditional formatting rule that would return a true
if the cell immediately to the left does not have a value exactly 1 less than
the value of "this cell."

My problem is that I can't find a function or reference operator for "this
cell" when applied to an entire column.

ie-
A B C
1
2 5 6 True
3 12 13 True
4 6 5 False
5 7 9 False

Conditional formatting applied to column B.

I looked at offset, but I need an absolute cell reference to offset from,
and I don't have that.

Thanks in advance