Daren
The -- can be used to cause Excel to convert strings that look like
numbers to numbers; which will allow the numeric calculations to
work. It serves the same purpose as the N() function.
That would be my guess.
Ken

On Oct 29, 5:11*pm, Daren wrote:
Hello,

The AND statement is as follows:

=and(--d2--c2,--c2--b2m--b2--a2). *

What's the purpose of the double unary here?

Thanks!