Yes if two of them are both global conversions (or both are skill mods) then you get 100 Chaos damage.
No, if one of them is a skill modifier (not global conversion skill mod added to a buff skill though) and the other one is global. Then you get 76 Chaos damage. Not sure if a partial Vit → Chaos skill mod exists in this game though but for some other damage types they definitely do.
Thank you for the help. I read some manuals and discussions, but I always had questions.
In a global conversion of damage A to damage B of magnitude 100% (obtained by equipment), then, in the game’s statistics, damage A is 0, as it was all converted into damage B. So, in this case, the question is whether a skill that deals 100 A damage would still be useful, since in the character’s statistics, A damage is 0.
But then, reading the manual indicated by you, I understood that, as it is a global conversion of equipment, first, the 100 damage A is converted into 100 damage B. Then the bonuses are added and recalculated based on the total type B damage. Do I understand correctly?