On relative and bi-relative algebraic K-theory of rings of finite characteristic

Throughout, we fix a prime number p and consider unital associative rings in which p is nilpotent. It was proved by Weibel [28, Cor. 5.3, Cor. 5.4] long ago that for such rings, the relative K-groups associated with a nilpotent extension and the bi-relative K-groups associated with a Milnor square are p-primary torsion groups