DEFINITION sc3_props__sc3_sn3_abst()
TYPE =
       ∀g:G
         .∀a:A
           .land
             ∀c:C.∀t:T.(sc3 g a c t)→(sn3 c t)
             ∀vs:TList
               .∀i:nat
                 .let t := THeads (Flat Appl) vs (TLRef i)
                 in ∀c:C.(arity g c t a)→(nf2 c (TLRef i))→(sns3 c vs)→(sc3 g a c t)
BODY =
        assume g: G
        assume a: A
          we proceed by induction on a to prove 
             land
               ∀c:C.∀t:T.(sc3 g a c t)→(sn3 c t)
               ∀vs:TList
                 .∀i:nat
                   .let t := THeads (Flat Appl) vs (TLRef i)
                   in ∀c:C.(arity g c t a)→(nf2 c (TLRef i))→(sns3 c vs)→(sc3 g a c t)
             case ASort : n:nat n0:nat ⇒
                the thesis becomes 
                land
                  ∀c:C.∀t:T.(sc3 g (ASort n n0) c t)→(sn3 c t)
                  ∀vs:TList
                    .∀i:nat
                      .let t := THeads (Flat Appl) vs (TLRef i)
                      in ∀c:C
                             .arity g c t (ASort n n0)
                               →(nf2 c (TLRef i))→(sns3 c vs)→(sc3 g (ASort n n0) c t)
                   (h1) 
                       assume c: C
                       assume t: T
                       suppose H: land (arity g c t (ASort n n0)) (sn3 c t)
                         (H0) consider H
                         we proceed by induction on H0 to prove sn3 c t
                            case conj : :arity g c t (ASort n n0) H2:sn3 c t ⇒
                               the thesis becomes the hypothesis H2
                         we proved sn3 c t
∀c:C.∀t:T.(land (arity g c t (ASort n n0)) (sn3 c t))→(sn3 c t)
                   end of h1
                   (h2) 
                       assume vs: TList
                       assume i: nat
                       assume c: C
                       suppose H: arity g c (THeads (Flat Appl) vs (TLRef i)) (ASort n n0)
                       suppose H0: nf2 c (TLRef i)
                       suppose H1: sns3 c vs
                         by (sn3_appls_lref . . H0 . H1)
                         we proved sn3 c (THeads (Flat Appl) vs (TLRef i))
                         by (conj . . H previous)
                         we proved 
                            land
                              arity g c (THeads (Flat Appl) vs (TLRef i)) (ASort n n0)
                              sn3 c (THeads (Flat Appl) vs (TLRef i))

                         ∀vs:TList
                           .∀i:nat
                             .∀c:C
                               .arity g c (THeads (Flat Appl) vs (TLRef i)) (ASort n n0)
                                 →(nf2 c (TLRef i)
                                      →(sns3 c vs
                                           →(land
                                                arity g c (THeads (Flat Appl) vs (TLRef i)) (ASort n n0)
                                                sn3 c (THeads (Flat Appl) vs (TLRef i)))))
                   end of h2
                   by (conj . . h1 h2)
                   we proved 
                      land
                        ∀c:C.∀t:T.(land (arity g c t (ASort n n0)) (sn3 c t))→(sn3 c t)
                        ∀vs:TList
                          .∀i:nat
                            .∀c:C
                              .arity g c (THeads (Flat Appl) vs (TLRef i)) (ASort n n0)
                                →(nf2 c (TLRef i)
                                     →(sns3 c vs
                                          →(land
                                               arity g c (THeads (Flat Appl) vs (TLRef i)) (ASort n n0)
                                               sn3 c (THeads (Flat Appl) vs (TLRef i)))))

                      land
                        ∀c:C.∀t:T.(sc3 g (ASort n n0) c t)→(sn3 c t)
                        ∀vs:TList
                          .∀i:nat
                            .let t := THeads (Flat Appl) vs (TLRef i)
                            in ∀c:C
                                   .arity g c t (ASort n n0)
                                     →(nf2 c (TLRef i))→(sns3 c vs)→(sc3 g (ASort n n0) c t)
             case AHead : a0:A a1:A ⇒
                the thesis becomes 
                land
                  ∀c:C.∀t:T.(sc3 g (AHead a0 a1) c t)→(sn3 c t)
                  ∀vs:TList
                    .∀i:nat
                      .let t := THeads (Flat Appl) vs (TLRef i)
                      in ∀c:C
                             .arity g c t (AHead a0 a1)
                               →(nf2 c (TLRef i))→(sns3 c vs)→(sc3 g (AHead a0 a1) c t)
                (H) by induction hypothesis we know 
                   land
                     ∀c:C.∀t:T.(sc3 g a0 c t)→(sn3 c t)
                     ∀vs:TList
                       .∀i:nat
                         .∀c:C
                           .arity g c (THeads (Flat Appl) vs (TLRef i)) a0
                             →(nf2 c (TLRef i)
                                  →(sns3 c vs)→(sc3 g a0 c (THeads (Flat Appl) vs (TLRef i))))
                (H0) by induction hypothesis we know 
                   land
                     ∀c:C.∀t:T.(sc3 g a1 c t)→(sn3 c t)
                     ∀vs:TList
                       .∀i:nat
                         .∀c:C
                           .arity g c (THeads (Flat Appl) vs (TLRef i)) a1
                             →(nf2 c (TLRef i)
                                  →(sns3 c vs)→(sc3 g a1 c (THeads (Flat Appl) vs (TLRef i))))
                   (h1) 
                       assume c: C
                       assume t: T
                       suppose H1: 
                          land
                            arity g c t (AHead a0 a1)
                            ∀d:C
                              .∀w:T
                                .sc3 g a0 d w
                                  →∀is:PList.(drop1 is d c)→(sc3 g a1 d (THead (Flat Appl) w (lift1 is t)))
                         (H2) consider H
                         we proceed by induction on H2 to prove sn3 c t
                            case conj : :∀c0:C.∀t0:T.(sc3 g a0 c0 t0)→(sn3 c0 t0) H4:∀vs:TList.∀i:nat.∀c0:C.(arity g c0 (THeads (Flat Appl) vs (TLRef i)) a0)→(nf2 c0 (TLRef i))→(sns3 c0 vs)→(sc3 g a0 c0 (THeads (Flat Appl) vs (TLRef i))) ⇒
                               the thesis becomes sn3 c t
                                  (H5) consider H0
                                  we proceed by induction on H5 to prove sn3 c t
                                     case conj : H6:∀c0:C.∀t0:T.(sc3 g a1 c0 t0)→(sn3 c0 t0) :∀vs:TList.∀i:nat.∀c0:C.(arity g c0 (THeads (Flat Appl) vs (TLRef i)) a1)→(nf2 c0 (TLRef i))→(sns3 c0 vs)→(sc3 g a1 c0 (THeads (Flat Appl) vs (TLRef i))) ⇒
                                        the thesis becomes sn3 c t
                                           (H8) consider H1
                                           we proceed by induction on H8 to prove sn3 c t
                                              case conj : H9:arity g c t (AHead a0 a1) H10:∀d:C.∀w:T.(sc3 g a0 d w)→∀is:PList.(drop1 is d c)→(sc3 g a1 d (THead (Flat Appl) w (lift1 is t))) ⇒
                                                 the thesis becomes sn3 c t
                                                    (H_y) 
                                                       by (arity_aprem . . . . H9 . .)

                                                          aprem O (AHead a0 a1) a0
                                                            →(ex2_3
                                                                 C
                                                                 T
                                                                 nat
                                                                 λd:C.λ:T.λj:nat.drop (plus O j) O d c
                                                                 λd:C.λu:T.λ:nat.arity g d u (asucc g a0))
                                                    end of H_y
                                                    (H11) 
                                                       by (aprem_zero . .)
                                                       we proved aprem O (AHead a0 a1) a0
                                                       by (H_y previous)

                                                          ex2_3
                                                            C
                                                            T
                                                            nat
                                                            λd:C.λ:T.λj:nat.drop (plus O j) O d c
                                                            λd:C.λu:T.λ:nat.arity g d u (asucc g a0)
                                                    end of H11
                                                    consider H11
                                                    we proved 
                                                       ex2_3
                                                         C
                                                         T
                                                         nat
                                                         λd:C.λ:T.λj:nat.drop (plus O j) O d c
                                                         λd:C.λu:T.λ:nat.arity g d u (asucc g a0)
                                                    that is equivalent to ex2_3 C T nat λd:C.λ:T.λj:nat.drop j O d c λd:C.λu:T.λ:nat.arity g d u (asucc g a0)
                                                    we proceed by induction on the previous result to prove sn3 c t
                                                       case ex2_3_intro : x0:C x1:T x2:nat H12:drop x2 O x0 c H13:arity g x0 x1 (asucc g a0) ⇒
                                                          the thesis becomes sn3 c t
                                                             (H_y0) 
                                                                (h1) 
                                                                   by (getl_refl . . .)
                                                                   we proved getl O (CHead x0 (Bind Abst) x1) (CHead x0 (Bind Abst) x1)
                                                                   by (arity_abst . . . . . previous . H13)
                                                                   we proved arity g (CHead x0 (Bind Abst) x1) (TLRef O) a0

                                                                      arity
                                                                        g
                                                                        CHead x0 (Bind Abst) x1
                                                                        THeads (Flat Appl) TNil (TLRef O)
                                                                        a0
                                                                end of h1
                                                                (h2) 
                                                                   by (getl_refl . . .)
                                                                   we proved getl O (CHead x0 (Bind Abst) x1) (CHead x0 (Bind Abst) x1)
                                                                   by (nf2_lref_abst . . . . previous)
nf2 (CHead x0 (Bind Abst) x1) (TLRef O)
                                                                end of h2
                                                                (h3) 
                                                                   consider I
                                                                   we proved True
sns3 (CHead x0 (Bind Abst) x1) TNil
                                                                end of h3
                                                                by (H4 . . . h1 h2 h3)
                                                                we proved 
                                                                   sc3
                                                                     g
                                                                     a0
                                                                     CHead x0 (Bind Abst) x1
                                                                     THeads (Flat Appl) TNil (TLRef O)
                                                                that is equivalent to sc3 g a0 (CHead x0 (Bind Abst) x1) (TLRef O)
                                                                by (H10 . . previous .)

                                                                   drop1 (PCons (S x2) O PNil) (CHead x0 (Bind Abst) x1) c
                                                                     →(sc3
                                                                          g
                                                                          a1
                                                                          CHead x0 (Bind Abst) x1
                                                                          THead (Flat Appl) (TLRef O) (lift1 (PCons (S x2) O PNil) t))
                                                             end of H_y0
                                                             (H_y1) 
                                                                (h1) 
                                                                   consider H12
                                                                   we proved drop x2 O x0 c
                                                                   that is equivalent to drop (r (Bind Abst) x2) O x0 c
                                                                   by (drop_drop . . . . previous .)
drop (S x2) O (CHead x0 (Bind Abst) x1) c
                                                                end of h1
                                                                (h2) 
                                                                   by (drop1_nil .)
drop1 PNil c c
                                                                end of h2
                                                                by (drop1_cons . . . . h1 . . h2)
                                                                we proved drop1 (PCons (S x2) O PNil) (CHead x0 (Bind Abst) x1) c
                                                                by (H_y0 previous)
                                                                we proved 
                                                                   sc3
                                                                     g
                                                                     a1
                                                                     CHead x0 (Bind Abst) x1
                                                                     THead (Flat Appl) (TLRef O) (lift1 (PCons (S x2) O PNil) t)
                                                                that is equivalent to 
                                                                   sc3
                                                                     g
                                                                     a1
                                                                     CHead x0 (Bind Abst) x1
                                                                     THead (Flat Appl) (TLRef O) (lift (S x2) O t)
                                                                by (H6 . . previous)

                                                                   sn3
                                                                     CHead x0 (Bind Abst) x1
                                                                     THead (Flat Appl) (TLRef O) (lift (S x2) O t)
                                                             end of H_y1
                                                             (H_x) 
                                                                by (sn3_gen_flat . . . . H_y1)

                                                                   land
                                                                     sn3 (CHead x0 (Bind Abst) x1) (TLRef O)
                                                                     sn3 (CHead x0 (Bind Abst) x1) (lift (S x2) O t)
                                                             end of H_x
                                                             (H14) consider H_x
                                                             we proceed by induction on H14 to prove sn3 c t
                                                                case conj : :sn3 (CHead x0 (Bind Abst) x1) (TLRef O) H16:sn3 (CHead x0 (Bind Abst) x1) (lift (S x2) O t) ⇒
                                                                   the thesis becomes sn3 c t
                                                                      consider H12
                                                                      we proved drop x2 O x0 c
                                                                      that is equivalent to drop (r (Bind Abst) x2) O x0 c
                                                                      by (drop_drop . . . . previous .)
                                                                      we proved drop (S x2) O (CHead x0 (Bind Abst) x1) c
                                                                      by (sn3_gen_lift . . . . H16 . previous)
sn3 c t
sn3 c t
sn3 c t
sn3 c t
sn3 c t
                         we proved sn3 c t

                         ∀c:C
                           .∀t:T
                             .(land
                                 arity g c t (AHead a0 a1)
                                 ∀d:C
                                   .∀w:T
                                     .sc3 g a0 d w
                                       →∀is:PList.(drop1 is d c)→(sc3 g a1 d (THead (Flat Appl) w (lift1 is t))))
                               →sn3 c t
                   end of h1
                   (h2) 
                       assume vs: TList
                       assume i: nat
                       assume c: C
                       suppose H1: arity g c (THeads (Flat Appl) vs (TLRef i)) (AHead a0 a1)
                       suppose H2: nf2 c (TLRef i)
                       suppose H3: sns3 c vs
                          assume d: C
                          assume w: T
                          suppose H4: sc3 g a0 d w
                          assume is: PList
                          suppose H5: drop1 is d c
                            (H6) consider H
                            we proceed by induction on H6 to prove 
                               sc3
                                 g
                                 a1
                                 d
                                 THead
                                   Flat Appl
                                   w
                                   lift1 is (THeads (Flat Appl) vs (TLRef i))
                               case conj : H7:∀c0:C.∀t:T.(sc3 g a0 c0 t)→(sn3 c0 t) :∀vs0:TList.∀i0:nat.∀c0:C.(arity g c0 (THeads (Flat Appl) vs0 (TLRef i0)) a0)→(nf2 c0 (TLRef i0))→(sns3 c0 vs0)→(sc3 g a0 c0 (THeads (Flat Appl) vs0 (TLRef i0))) ⇒
                                  the thesis becomes 
                                  sc3
                                    g
                                    a1
                                    d
                                    THead
                                      Flat Appl
                                      w
                                      lift1 is (THeads (Flat Appl) vs (TLRef i))
                                     (H9) consider H0
                                     we proceed by induction on H9 to prove 
                                        sc3
                                          g
                                          a1
                                          d
                                          THead
                                            Flat Appl
                                            w
                                            lift1 is (THeads (Flat Appl) vs (TLRef i))
                                        case conj : :∀c0:C.∀t:T.(sc3 g a1 c0 t)→(sn3 c0 t) H11:∀vs0:TList.∀i0:nat.∀c0:C.(arity g c0 (THeads (Flat Appl) vs0 (TLRef i0)) a1)→(nf2 c0 (TLRef i0))→(sns3 c0 vs0)→(sc3 g a1 c0 (THeads (Flat Appl) vs0 (TLRef i0))) ⇒
                                           the thesis becomes 
                                           sc3
                                             g
                                             a1
                                             d
                                             THead
                                               Flat Appl
                                               w
                                               lift1 is (THeads (Flat Appl) vs (TLRef i))
                                              (H_y) 
                                                 by (H11 .)

                                                    ∀i0:nat
                                                      .∀c0:C
                                                        .arity g c0 (THeads (Flat Appl) (TCons w (lifts1 is vs)) (TLRef i0)) a1
                                                          →(nf2 c0 (TLRef i0)
                                                               →(sns3 c0 (TCons w (lifts1 is vs))
                                                                    →sc3 g a1 c0 (THeads (Flat Appl) (TCons w (lifts1 is vs)) (TLRef i0))))
                                              end of H_y
                                              (h1) 
                                                 (h1) 
                                                    (h1) 
                                                       by (lift1_lref . .)
                                                       we proved eq T (lift1 is (TLRef i)) (TLRef (trans is i))
                                                       we proceed by induction on the previous result to prove 
                                                          arity
                                                            g
                                                            d
                                                            THead
                                                              Flat Appl
                                                              w
                                                              THeads (Flat Appl) (lifts1 is vs) (TLRef (trans is i))
                                                            a1
                                                          case refl_equal : ⇒
                                                             the thesis becomes 
                                                             arity
                                                               g
                                                               d
                                                               THead
                                                                 Flat Appl
                                                                 w
                                                                 THeads (Flat Appl) (lifts1 is vs) (lift1 is (TLRef i))
                                                               a1
                                                                by (lifts1_flat . . . .)
                                                                we proved 
                                                                   eq
                                                                     T
                                                                     lift1 is (THeads (Flat Appl) vs (TLRef i))
                                                                     THeads (Flat Appl) (lifts1 is vs) (lift1 is (TLRef i))
                                                                we proceed by induction on the previous result to prove 
                                                                   arity
                                                                     g
                                                                     d
                                                                     THead
                                                                       Flat Appl
                                                                       w
                                                                       THeads (Flat Appl) (lifts1 is vs) (lift1 is (TLRef i))
                                                                     a1
                                                                   case refl_equal : ⇒
                                                                      the thesis becomes 
                                                                      arity
                                                                        g
                                                                        d
                                                                        THead
                                                                          Flat Appl
                                                                          w
                                                                          lift1 is (THeads (Flat Appl) vs (TLRef i))
                                                                        a1
                                                                         (h1) 
                                                                            by (sc3_arity_gen . . . . H4)
arity g d w a0
                                                                         end of h1
                                                                         (h2) 
                                                                            by (arity_lift1 . . . . . . H5 H1)
arity g d (lift1 is (THeads (Flat Appl) vs (TLRef i))) (AHead a0 a1)
                                                                         end of h2
                                                                         by (arity_appl . . . . h1 . . h2)

                                                                            arity
                                                                              g
                                                                              d
                                                                              THead
                                                                                Flat Appl
                                                                                w
                                                                                lift1 is (THeads (Flat Appl) vs (TLRef i))
                                                                              a1

                                                                   arity
                                                                     g
                                                                     d
                                                                     THead
                                                                       Flat Appl
                                                                       w
                                                                       THeads (Flat Appl) (lifts1 is vs) (lift1 is (TLRef i))
                                                                     a1
                                                       we proved 
                                                          arity
                                                            g
                                                            d
                                                            THead
                                                              Flat Appl
                                                              w
                                                              THeads (Flat Appl) (lifts1 is vs) (TLRef (trans is i))
                                                            a1

                                                          arity
                                                            g
                                                            d
                                                            THeads (Flat Appl) (TCons w (lifts1 is vs)) (TLRef (trans is i))
                                                            a1
                                                    end of h1
                                                    (h2) 
                                                       by (lift1_lref . .)
                                                       we proved eq T (lift1 is (TLRef i)) (TLRef (trans is i))
                                                       we proceed by induction on the previous result to prove nf2 d (TLRef (trans is i))
                                                          case refl_equal : ⇒
                                                             the thesis becomes nf2 d (lift1 is (TLRef i))
                                                                by (nf2_lift1 . . . . H5 H2)
nf2 d (lift1 is (TLRef i))
nf2 d (TLRef (trans is i))
                                                    end of h2
                                                    (h3) 
                                                       (h1) by (H7 . . H4) we proved sn3 d w
                                                       (h2) 
                                                          by (sns3_lifts1 . . . H5 . H3)
sns3 d (lifts1 is vs)
                                                       end of h2
                                                       by (conj . . h1 h2)
                                                       we proved land (sn3 d w) (sns3 d (lifts1 is vs))
sns3 d (TCons w (lifts1 is vs))
                                                    end of h3
                                                    by (H_y . . h1 h2 h3)
                                                    we proved 
                                                       sc3
                                                         g
                                                         a1
                                                         d
                                                         THeads (Flat Appl) (TCons w (lifts1 is vs)) (TLRef (trans is i))

                                                       sc3
                                                         g
                                                         a1
                                                         d
                                                         THead
                                                           Flat Appl
                                                           w
                                                           THeads (Flat Appl) (lifts1 is vs) (TLRef (trans is i))
                                                 end of h1
                                                 (h2) 
                                                    by (lift1_lref . .)
eq T (lift1 is (TLRef i)) (TLRef (trans is i))
                                                 end of h2
                                                 by (eq_ind_r . . . h1 . h2)

                                                    sc3
                                                      g
                                                      a1
                                                      d
                                                      THead
                                                        Flat Appl
                                                        w
                                                        THeads (Flat Appl) (lifts1 is vs) (lift1 is (TLRef i))
                                              end of h1
                                              (h2) 
                                                 by (lifts1_flat . . . .)

                                                    eq
                                                      T
                                                      lift1 is (THeads (Flat Appl) vs (TLRef i))
                                                      THeads (Flat Appl) (lifts1 is vs) (lift1 is (TLRef i))
                                              end of h2
                                              by (eq_ind_r . . . h1 . h2)

                                                 sc3
                                                   g
                                                   a1
                                                   d
                                                   THead
                                                     Flat Appl
                                                     w
                                                     lift1 is (THeads (Flat Appl) vs (TLRef i))

                                        sc3
                                          g
                                          a1
                                          d
                                          THead
                                            Flat Appl
                                            w
                                            lift1 is (THeads (Flat Appl) vs (TLRef i))
                            we proved 
                               sc3
                                 g
                                 a1
                                 d
                                 THead
                                   Flat Appl
                                   w
                                   lift1 is (THeads (Flat Appl) vs (TLRef i))
                         we proved 
                            ∀d:C
                              .∀w:T
                                .sc3 g a0 d w
                                  →∀is:PList
                                       .drop1 is d c
                                         →(sc3
                                              g
                                              a1
                                              d
                                              THead
                                                Flat Appl
                                                w
                                                lift1 is (THeads (Flat Appl) vs (TLRef i)))
                         by (conj . . H1 previous)
                         we proved 
                            land
                              arity g c (THeads (Flat Appl) vs (TLRef i)) (AHead a0 a1)
                              ∀d:C
                                .∀w:T
                                  .sc3 g a0 d w
                                    →∀is:PList
                                         .drop1 is d c
                                           →(sc3
                                                g
                                                a1
                                                d
                                                THead
                                                  Flat Appl
                                                  w
                                                  lift1 is (THeads (Flat Appl) vs (TLRef i)))

                         ∀vs:TList
                           .∀i:nat
                             .∀c:C
                               .arity g c (THeads (Flat Appl) vs (TLRef i)) (AHead a0 a1)
                                 →(nf2 c (TLRef i)
                                      →(sns3 c vs
                                           →(land
                                                arity g c (THeads (Flat Appl) vs (TLRef i)) (AHead a0 a1)
                                                ∀d:C
                                                  .∀w:T
                                                    .sc3 g a0 d w
                                                      →∀is:PList
                                                           .drop1 is d c
                                                             →(sc3
                                                                  g
                                                                  a1
                                                                  d
                                                                  THead
                                                                    Flat Appl
                                                                    w
                                                                    lift1 is (THeads (Flat Appl) vs (TLRef i))))))
                   end of h2
                   by (conj . . h1 h2)
                   we proved 
                      land
                        ∀c:C
                          .∀t:T
                            .(land
                                arity g c t (AHead a0 a1)
                                ∀d:C
                                  .∀w:T
                                    .sc3 g a0 d w
                                      →∀is:PList.(drop1 is d c)→(sc3 g a1 d (THead (Flat Appl) w (lift1 is t))))
                              →sn3 c t
                        ∀vs:TList
                          .∀i:nat
                            .∀c:C
                              .arity g c (THeads (Flat Appl) vs (TLRef i)) (AHead a0 a1)
                                →(nf2 c (TLRef i)
                                     →(sns3 c vs
                                          →(land
                                               arity g c (THeads (Flat Appl) vs (TLRef i)) (AHead a0 a1)
                                               ∀d:C
                                                 .∀w:T
                                                   .sc3 g a0 d w
                                                     →∀is:PList
                                                          .drop1 is d c
                                                            →(sc3
                                                                 g
                                                                 a1
                                                                 d
                                                                 THead
                                                                   Flat Appl
                                                                   w
                                                                   lift1 is (THeads (Flat Appl) vs (TLRef i))))))

                      land
                        ∀c:C.∀t:T.(sc3 g (AHead a0 a1) c t)→(sn3 c t)
                        ∀vs:TList
                          .∀i:nat
                            .let t := THeads (Flat Appl) vs (TLRef i)
                            in ∀c:C
                                   .arity g c t (AHead a0 a1)
                                     →(nf2 c (TLRef i))→(sns3 c vs)→(sc3 g (AHead a0 a1) c t)
          we proved 
             land
               ∀c:C.∀t:T.(sc3 g a c t)→(sn3 c t)
               ∀vs:TList
                 .∀i:nat
                   .let t := THeads (Flat Appl) vs (TLRef i)
                   in ∀c:C.(arity g c t a)→(nf2 c (TLRef i))→(sns3 c vs)→(sc3 g a c t)
       we proved 
          ∀g:G
            .∀a:A
              .land
                ∀c:C.∀t:T.(sc3 g a c t)→(sn3 c t)
                ∀vs:TList
                  .∀i:nat
                    .let t := THeads (Flat Appl) vs (TLRef i)
                    in ∀c:C.(arity g c t a)→(nf2 c (TLRef i))→(sns3 c vs)→(sc3 g a c t)