Definition sf_SF_val_fun (f : R -> R) (a b : R) (n : nat) : StepFun a b.

Lemma SF_val_subdiv_val (f : R -> R) (a b : R) (n : nat) : subdivision_val (sf_SF_val_fun f a b n) = match (Rle_dec a b) with | left _ => seq2Rlist (SF_val_ly f a b n) | right _ => seq2Rlist (SF_val_ly f b a n) end.