Penetration, Lower res calculation order [question]

What is the order of this calculation? Does Pen apply after lower resist from other sources like curse/exposure negating it if the latter is high enough? To clarify:

Pen = 30%
Lowered Resistance = 50%
Mob resist = 40%

My interpretation:

step 1: MobRes - LoweredRes = 40-50 = -10%
step 2: FianalMobRes - Pen = -10% is lower than 0, pen cannot go below 0%, Final Mitigation = -10%, penetration is ignored.

Is this correct?

yes

Not completely sure but since you get the mob into negative resistance with exposure/curse (-10% in your example) then penetration is completely ignored, you're dealing 10% extra dmg of that element thanks to lowered res.

If a mob instead has 50% res and you curse him with -25% (he now has 25% res) 5% of penetration will be ignored.

Penetration goes last if you're applying debuffs too.

Things change if you use Leopold's Applause which allow penetration to go down -50%.

If a mob has 30% res and you got 75% penetration, you'll be dealing 45% extra dmg without exposure/curses thanks to those gloves.

Correct me if i'm wrong.

thank you for clarifying guys.