Lemma expf_B0_CS_1_a_prel1:forall (m:fmap)(x:dart)(i j:nat), inv_hmap m -> succ m zero x -> let x_1 := cA_1 m one x in let p := MF.Iter_upb m x_1 in let xb0 := bottom m zero x in let z := Iter (cF m) i x_1 in xb0 = Iter (cF m) j x_1 -> (i <= j < p)%nat -> expf (B m zero x) x_1 z.