Small supplements, weak supplements and proper classes
Small supplements, weak supplements and proper classes
Let $ \mathcal{S} \mathcal{S} $ denote the class of short exact sequences $E :0 \to A bar{f} \to C\to 0 $ of R-modules and R-module homomorphisms such that f(A) has a small supplement in B i.e. there exists a submodule K of M such that f(A) +K = B and …