rattac.
inversion H1; clear H1; subst.
inversion H0; clear H0; subst.
inversion H; clear H; subst.
arithNormalize.
f_equal.
do 5 arithSimplify.
do 5 arithSimplify.
Qed.

(* Specifications: *)
Theorem num_dem_same_rat1 : forall n d,
n = posnatToNat d ->
RatIntro n  d == rat1.