Ignore def doesn't stack

i have the crusader set equipped, and a range of 7002~10003, no berzerk on, so what i deal is what it is. assuming the 25% PDR, my maximum possible damage would be 7502.25, and my minimum if the monster book effect of ignore 15% PDR applies, would be 5514.07, if i hit over the first number, PDR applied, if i went under the second, PDR didn't apply, in the SS you can see me hitting a good 100 damage under it.

do note i wasn't even accounting my 5.5% PDR ignore from ambition, which would make the numbers even higher, so i guess this also backs the theory of "it doesn't stack"

oh, weapon potential is +15 int. no lines or anything with damage/%PDR ignore

Pretty much concurring this. I did 6770 damage on a 25% PDR Dojo boss with a minimum range of 9001 and Ignore 30% PDR on the book.
9001 * (1 - (0.25*0.7)) = 7425
9001 * (1 - 0.25) = 6750