For a papal resignation to be valid, the pope must renounce his office (munus).
But in his Declaratio of resignation Pope Benedict XVI did not renounce his office (munus).
Therefore, Pope Benedict XVI’s resignation was not valid.
Proof of the major
Canon 332 Section 2 of the 1983 Code of Canon Law states the following:
“Should it happen that the Roman Pontiff resigns from his office, it is required for validity that the resignation be freely made and properly manifested, but it is not necessary that it be accepted by anyone.”
Proof of the minor
In his Declaratio, Pope Benedict XVI stated:
“I renounce the ministry…..”
The office of the papacy and the ministry of the papacy are not the same thing. The office is the soul of the papacy. The ministry is the active exercise of the powers of the office of the papacy,