3 Way match

Hi Every one

i looked at SCN bt did not find any answer .

We raise PO as net without Tax and do GR .

We have activated 3 way match.

I would like to knwo whether 3 way match include tax on invoices ,

So example

PO value 100 ( exclude tax)

GR    100

IR 110 ( 100 plus 100 )

So when we do 3 way match system will just look at 100 in 3 way match ,

many Thanks