fact: Definition module_kernel {R : ring} {A B : module R} (f : modulefun A B) : submodule A := make_submodule _ (issubmodule_kernel f).
imports: UniMath.MoreFoundations.Subtypes UniMath.Algebra.RigsAndRings UniMath.Algebra.Monoids UniMath.Algebra.Groups UniMath.Algebra.Modules.Core