fact: Definition linear_for (R : ringType) (U : lmodType R) (V : zmodType) (s : R -> V -> V) (f : U -> V) := forall a, {morph f : u v / a *: u + v >-> s a u + v}.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)