proposition: Fact der_opp f (x v : V) : derivable f x v -> (fun h => h^-1 *: (((- f) \o shift x) (h *: v) - (- f) x)) @ 0^' --> - 'D_v f x.
proof: Proof. move=> df; evar (g : R -> W); rewrite [X in X @ _](_ : _ = g) /=; last first. by rewrite funeqE => h; rewrite !scalerDr !scalerN -opprD -scalerBr /g. exact: cvgN. Qed.
imports: HB(structures) mathcomp(all_ssreflect ssralg ssrnum matrix interval) mathcomp(mathcomp_extra boolp classical_sets functions) reals signed topology prodnormedzmodule normedtype landau forms