+napply (R2 ?? ? ???? e0 ? e1);
+napply a3;
+nqed.
+
+(* include "nat/nat.ma".
+
+ninductive nlist : nat → Type[0] ≝
+| nnil : nlist O
+| ncons : ∀n:nat.nat → nlist n → nlist (S n).
+
+ninductive wrapper : Type[0] ≝
+| kw1 : ∀x.∀y:nlist x.wrapper
+| kw2 : ∀x.∀y:nlist x.wrapper.
+
+nlemma fie : ∀a,b,c,d.∀e:eq ? (kw1 a b) (kw1 c d).
+ ∀P:(∀x1.∀x2:nlist x1. ∀y1.∀y2:nlist y1.eq ? (kw1 x1 x2) (kw1 y1 y2) → Prop).
+ P a b a b (refl ??) → P a b c d e.
+#a;#b;#c;#d;#e;#P;#HP;
+ndiscriminate e;#e0;
+nsubst e0;#e1;
+nsubst e1;#E;
+(* nsubst E; purtroppo al momento funziona solo nel verso sbagliato *)
+nrewrite > E;
+napply HP;
+nqed.*)
+
+(***************)
+
+ninductive I1 : Type[0] ≝
+| k1 : I1.
+
+ninductive I2 : I1 → Type[0] ≝
+| k2 : ∀x.I2 x.
+
+ninductive I3 : ∀x:I1.I2 x → Type[0] ≝
+| k3 : ∀x,y.I3 x y.
+
+ninductive I4 : ∀x,y.I3 x y → Type[0] ≝
+| k4 : ∀x,y.∀z:I3 x y.I4 x y z.
+
+(*alias id "eq" = "cic:/matita/ng/logic/equality/eq.ind(1,0,2)".
+alias id "refl" = "cic:/matita/ng/logic/equality/eq.con(0,1,2)".*)
+
+ndefinition R4 :
+ ∀T0:Type[0].
+ ∀a0:T0.
+ ∀T1:∀x0:T0. eq T0 a0 x0 → Type[0].
+ ∀a1:T1 a0 (refl T0 a0).
+ ∀T2:∀x0:T0. ∀p0:eq (T0 …) a0 x0. ∀x1:T1 x0 p0.eq (T1 …) (R1 T0 a0 T1 a1 x0 p0) x1 → Type[0].
+ ∀a2:T2 a0 (refl T0 a0) a1 (refl (T1 a0 (refl T0 a0)) a1).
+ ∀T3:∀x0:T0. ∀p0:eq (T0 …) a0 x0. ∀x1:T1 x0 p0.∀p1:eq (T1 …) (R1 T0 a0 T1 a1 x0 p0) x1.
+ ∀x2:T2 x0 p0 x1 p1.eq (T2 …) (R2 T0 a0 T1 a1 T2 a2 x0 p0 x1 p1) x2 → Type[0].
+ ∀a3:T3 a0 (refl T0 a0) a1 (refl (T1 a0 (refl T0 a0)) a1)
+ a2 (refl (T2 a0 (refl T0 a0) a1 (refl (T1 a0 (refl T0 a0)) a1)) a2).
+ ∀T4:∀x0:T0. ∀p0:eq (T0 …) a0 x0. ∀x1:T1 x0 p0.∀p1:eq (T1 …) (R1 T0 a0 T1 a1 x0 p0) x1.
+ ∀x2:T2 x0 p0 x1 p1.∀p2:eq (T2 …) (R2 T0 a0 T1 a1 T2 a2 x0 p0 x1 p1) x2.
+ ∀x3:T3 x0 p0 x1 p1 x2 p2.∀p3:eq (T3 …) (R3 T0 a0 T1 a1 T2 a2 T3 a3 x0 p0 x1 p1 x2 p2) x3.
+ Type[0].
+ ∀a4:T4 a0 (refl T0 a0) a1 (refl (T1 a0 (refl T0 a0)) a1)
+ a2 (refl (T2 a0 (refl T0 a0) a1 (refl (T1 a0 (refl T0 a0)) a1)) a2)
+ a3 (refl (T3 a0 (refl T0 a0) a1 (refl (T1 a0 (refl T0 a0)) a1)
+ a2 (refl (T2 a0 (refl T0 a0) a1 (refl (T1 a0 (refl T0 a0)) a1)) a2))
+ a3).
+ ∀b0:T0.
+ ∀e0:eq (T0 …) a0 b0.
+ ∀b1: T1 b0 e0.
+ ∀e1:eq (T1 …) (R1 T0 a0 T1 a1 b0 e0) b1.
+ ∀b2: T2 b0 e0 b1 e1.
+ ∀e2:eq (T2 …) (R2 T0 a0 T1 a1 T2 a2 b0 e0 b1 e1) b2.
+ ∀b3: T3 b0 e0 b1 e1 b2 e2.
+ ∀e3:eq (T3 …) (R3 T0 a0 T1 a1 T2 a2 T3 a3 b0 e0 b1 e1 b2 e2) b3.
+ T4 b0 e0 b1 e1 b2 e2 b3 e3.
+#T0;#a0;#T1;#a1;#T2;#a2;#T3;#a3;#T4;#a4;#b0;#e0;#b1;#e1;#b2;#e2;#b3;#e3;
+napply (eq_rect_Type0 ????? e3);
+napply (R3 ????????? e0 ? e1 ? e2);
+napply a4;
+nqed.
+
+
+ninductive II : Type[0] ≝
+| kII1 : ∀x,y,z.∀w:I4 x y z.II
+| kII2 : ∀x,y,z.∀w:I4 x y z.II.
+
+(* nlemma foo : ∀a,b,c,d,e,f,g,h. kII1 a b c d = kII2 e f g h → True.
+#a;#b;#c;#d;#e;#f;#g;#h;#H;
+ndiscriminate H;
+nqed. *)
+
+nlemma faof : ∀a,b,c,d,e,f,g,h.∀Heq:kII1 a b c d = kII1 e f g h.
+ ∀P:(∀a,b,c,d.kII1 a b c d = kII1 e f g h → Prop).
+ P e f g h (refl ??) → P a b c d Heq.
+#a;#b;#c;#d;#e;#f;#g;#h;#Heq;#P;#HP;
+ndestruct;
+napply HP;
+nqed.