My players are, through inventive hypothetical spells, trying to understand the limits and nature of magic resistance.
Given ArM5's version of parma magica and an awareness of the pink dot loophole, how does magic air, suffocation, and the parma magica work?
For sake of argument, let us presume a stockade parma that cannot be lowered, and a sealed room that does not have access to refreshing breezes that is within an unfriendly Aegis otherwise inhibiting spellcasting.
Therefore, Without introducing house rules, what must be cast on the air in the room in order to suffocate a magi sealed in the room?
Note well that earlier editions of Ars Magica used a different (dispelling instead of repelling) version of the Parma Magica and I am not seeking those answers. Please cite your sources. Answers without citations will be downvoted.
Note also that this is not a Newtonian physics question. Sources describing the Aristotelian paradigm only, please.