(** Composition by linear functions *)

Lemma Lim_comp_lin (f : R -> R) (a b : R) (x : Rbar) :
ex_lim f (Rbar_plus (Rbar_mult a x) b) -> a <> 0 ->
Lim (fun y => f (a * y + b)) x = Lim f (Rbar_plus (Rbar_mult a x) b).