Working with SUMPRODUCT for the first time. Can someone explain the use of
the dashes following the command? I've seen from none to (I think) 4...

I started with: SUMPRODUCT(--(range=x),--(range=y))

I am currently trying to use 3 arguments, but the answer I expected was +#,
but I am getting a -#.

SUMPRODUCT(---([RANGE S]="REPORT"),---([RANGE 1 DUE]=[FIRST OF THE
MONTH],---([RANGE 1 DUE]<=[END OF THE MONTH]))

The actual answer is 2, but I get -2.