(** Another well-used function for having the logarithm of a real number x to the base #&beta;# *)
Record ln_beta_prop x := {
  ln_beta_val :> Z ;
  _ : (x <> 0)%R -> (bpow (ln_beta_val - 1)%Z <= Rabs x < bpow ln_beta_val)%R
}.(** Another well-used function for having the logarithm of a real number x to the base #&beta;# *)
Record ln_beta_prop x := {
  ln_beta_val :> Z ;
  _ : (x <> 0)%R -> (bpow (ln_beta_val - 1)%Z <= Rabs x < bpow ln_beta_val)%R
}.Definition ln_beta :
  forall x : R, ln_beta_prop x.

(* Specifications: *)
Theorem bpow_lt_bpow : forall e1 e2, (bpow (e1 - 1) < bpow e2)%R -> (e1 <= e2)%Z.
Theorem bpow_unique : forall x e1 e2, (bpow (e1 - 1) <= x < bpow e1)%R -> (bpow (e2 - 1) <= x < bpow e2)%R -> e1 = e2.
Theorem ln_beta_unique : forall (x : R) (e : Z), (bpow (e - 1) <= Rabs x < bpow e)%R -> ln_beta x = e :> Z.
Theorem ln_beta_opp : forall x, ln_beta (-x) = ln_beta x :> Z.
Theorem ln_beta_abs : forall x, ln_beta (Rabs x) = ln_beta x :> Z.
Theorem ln_beta_unique_pos : forall (x : R) (e : Z), (bpow (e - 1) <= x < bpow e)%R -> ln_beta x = e :> Z.
Theorem ln_beta_le_abs : forall x y, (x <> 0)%R -> (Rabs x <= Rabs y)%R -> (ln_beta x <= ln_beta y)%Z.
Theorem ln_beta_le : forall x y, (0 < x)%R -> (x <= y)%R -> (ln_beta x <= ln_beta y)%Z.
Lemma ln_beta_lt_pos : forall x y, (0 < y)%R -> (ln_beta x < ln_beta y)%Z -> (x < y)%R.
Theorem ln_beta_bpow : forall e, (ln_beta (bpow e) = e + 1 :> Z)%Z.
Theorem ln_beta_mult_bpow : forall x e, x <> 0%R -> (ln_beta (x * bpow e) = ln_beta x + e :>Z)%Z.
Theorem ln_beta_le_bpow : forall x e, x <> 0%R -> (Rabs x < bpow e)%R -> (ln_beta x <= e)%Z.
Theorem ln_beta_gt_bpow : forall x e, (bpow e <= Rabs x)%R -> (e < ln_beta x)%Z.
Theorem ln_beta_ge_bpow : forall x e, (bpow (e - 1) <= Rabs x)%R -> (e <= ln_beta x)%Z.
Theorem bpow_ln_beta_gt : forall x, (Rabs x < bpow (ln_beta x))%R.
Theorem bpow_ln_beta_le : forall x, (x <> 0)%R -> (bpow (ln_beta x-1) <= Rabs x)%R.
Theorem ln_beta_le_Zpower : forall m e, m <> Z0 -> (Zabs m < Zpower r e)%Z-> (ln_beta (Z2R m) <= e)%Z.
Theorem ln_beta_gt_Zpower : forall m e, m <> Z0 -> (Zpower r e <= Zabs m)%Z -> (e < ln_beta (Z2R m))%Z.
Lemma ln_beta_mult : forall x y, (x <> 0)%R -> (y <> 0)%R -> (ln_beta x + ln_beta y - 1 <= ln_beta (x * y) <= ln_beta x + ln_beta y)%Z.
Lemma ln_beta_plus : forall x y, (0 < y)%R -> (y <= x)%R -> (ln_beta x <= ln_beta (x + y) <= ln_beta x + 1)%Z.
Lemma ln_beta_minus : forall x y, (0 < y)%R -> (y < x)%R -> (ln_beta (x - y) <= ln_beta x)%Z.
Lemma ln_beta_minus_lb : forall x y, (0 < x)%R -> (0 < y)%R -> (ln_beta y <= ln_beta x - 2)%Z -> (ln_beta x - 1 <= ln_beta (x - y))%Z.
Lemma ln_beta_div : forall x y : R, (0 < x)%R -> (0 < y)%R -> (ln_beta x - ln_beta y <= ln_beta (x / y) <= ln_beta x - ln_beta y + 1)%Z.
Lemma ln_beta_sqrt : forall x, (0 < x)%R -> (2 * ln_beta (sqrt x) - 1 <= ln_beta x <= 2 * ln_beta (sqrt x))%Z.
Theorem eqb_sym : forall x y, Bool.eqb x y = Bool.eqb y x.
Theorem eqb_false : forall x y, x = negb y -> Bool.eqb x y = false.
Theorem eqb_true : forall x y, x = y -> Bool.eqb x y = true.