DEFINITION ty3_ind()
TYPE =
       g:G
         .P:CTTProp
           .c:C
               .t:T
                 .t1:T
                   .ty3 g c t t1
                     (P c t t1)t2:T.t3:T.(ty3 g c t2 t3)(P c t2 t3)(pc3 c t3 t)(P c t2 t)
             (c:C.n:nat.(P c (TSort n) (TSort (next g n)))
                  (n:nat
                         .c:C
                           .c1:C
                             .t:T
                               .getl n c (CHead c1 (Bind Abbr) t)
                                 t1:T.(ty3 g c1 t t1)(P c1 t t1)(P c (TLRef n) (lift (S n) O t1))
                       (n:nat
                              .c:C
                                .c1:C
                                  .t:T
                                    .getl n c (CHead c1 (Bind Abst) t)
                                      t1:T.(ty3 g c1 t t1)(P c1 t t1)(P c (TLRef n) (lift (S n) O t))
                            (c:C
                                   .t:T
                                     .t1:T
                                       .ty3 g c t t1
                                         (P c t t1
                                              b:B
                                                   .t2:T
                                                     .t3:T
                                                       .ty3 g (CHead c (Bind b) t) t2 t3
                                                         (P (CHead c (Bind b) t) t2 t3
                                                              P c (THead (Bind b) t t2) (THead (Bind b) t t3)))
                                 (c:C
                                        .t:T
                                          .t1:T
                                            .ty3 g c t t1
                                              (P c t t1
                                                   t2:T
                                                        .t3:T
                                                          .ty3 g c t2 (THead (Bind Abst) t1 t3)
                                                            (P c t2 (THead (Bind Abst) t1 t3)
                                                                 (P
                                                                      c
                                                                      THead (Flat Appl) t t2
                                                                      THead (Flat Appl) t (THead (Bind Abst) t1 t3))))
                                      (c:C
                                             .t:T
                                               .t1:T
                                                 .ty3 g c t t1
                                                   (P c t t1
                                                        t2:T
                                                             .ty3 g c t1 t2
                                                               (P c t1 t2)(P c (THead (Flat Cast) t1 t) (THead (Flat Cast) t2 t1)))
                                           c:C.t:T.t1:T.(ty3 g c t t1)(P c t t1)))))))
BODY =
        assume gG
        assume PCTTProp
        suppose H
           c:C
             .t:T
               .t1:T
                 .ty3 g c t t1
                   (P c t t1)t2:T.t3:T.(ty3 g c t2 t3)(P c t2 t3)(pc3 c t3 t)(P c t2 t)
        suppose H1c:C.n:nat.(P c (TSort n) (TSort (next g n)))
        suppose H2
           n:nat
             .c:C
               .c1:C
                 .t:T
                   .getl n c (CHead c1 (Bind Abbr) t)
                     t1:T.(ty3 g c1 t t1)(P c1 t t1)(P c (TLRef n) (lift (S n) O t1))
        suppose H3
           n:nat
             .c:C
               .c1:C
                 .t:T
                   .getl n c (CHead c1 (Bind Abst) t)
                     t1:T.(ty3 g c1 t t1)(P c1 t t1)(P c (TLRef n) (lift (S n) O t))
        suppose H4
           c:C
             .t:T
               .t1:T
                 .ty3 g c t t1
                   (P c t t1
                        b:B
                             .t2:T
                               .t3:T
                                 .ty3 g (CHead c (Bind b) t) t2 t3
                                   (P (CHead c (Bind b) t) t2 t3
                                        P c (THead (Bind b) t t2) (THead (Bind b) t t3)))
        suppose H5
           c:C
             .t:T
               .t1:T
                 .ty3 g c t t1
                   (P c t t1
                        t2:T
                             .t3:T
                               .ty3 g c t2 (THead (Bind Abst) t1 t3)
                                 (P c t2 (THead (Bind Abst) t1 t3)
                                      (P
                                           c
                                           THead (Flat Appl) t t2
                                           THead (Flat Appl) t (THead (Bind Abst) t1 t3))))
        suppose H6
           c:C
             .t:T
               .t1:T
                 .ty3 g c t t1
                   (P c t t1
                        t2:T
                             .ty3 g c t1 t2
                               (P c t1 t2)(P c (THead (Flat Cast) t1 t) (THead (Flat Cast) t2 t1)))
          (aux) by well-founded reasoning we prove c:C.t:T.t1:T.(ty3 g c t t1)(P c t t1)
           assume cC
           assume tT
           assume t1T
           suppose H7ty3 g c t t1
             by cases on H7 we prove P c t t1
                case ty3_conv c1:C t2:T t3:T H8:ty3 g c1 t2 t3 t4:T t5:T H9:ty3 g c1 t4 t5 H10:pc3 c1 t5 t2 
                   the thesis becomes P c1 t4 t2
                   (h1by (aux . . . H8) we proved P c1 t2 t3
                   (h2by (aux . . . H9) we proved P c1 t4 t5
                   by (H . . . H8 h1 . . H9 h2 H10)
P c1 t4 t2
                case ty3_sort c1:C n:nat 
                   the thesis becomes P c1 (TSort n) (TSort (next g n))
                   by (H1 . .)
P c1 (TSort n) (TSort (next g n))
                case ty3_abbr n:nat c1:C c2:C t2:T H8:getl n c1 (CHead c2 (Bind Abbr) t2) t3:T H9:ty3 g c2 t2 t3 
                   the thesis becomes P c1 (TLRef n) (lift (S n) O t3)
                   by (aux . . . H9)
                   we proved P c2 t2 t3
                   by (H2 . . . . H8 . H9 previous)
P c1 (TLRef n) (lift (S n) O t3)
                case ty3_abst n:nat c1:C c2:C t2:T H8:getl n c1 (CHead c2 (Bind Abst) t2) t3:T H9:ty3 g c2 t2 t3 
                   the thesis becomes P c1 (TLRef n) (lift (S n) O t2)
                   by (aux . . . H9)
                   we proved P c2 t2 t3
                   by (H3 . . . . H8 . H9 previous)
P c1 (TLRef n) (lift (S n) O t2)
                case ty3_bind c1:C t2:T t3:T H8:ty3 g c1 t2 t3 b:B t4:T t5:T H9:ty3 g (CHead c1 (Bind b) t2) t4 t5 
                   the thesis becomes P c1 (THead (Bind b) t2 t4) (THead (Bind b) t2 t5)
                   (h1by (aux . . . H8) we proved P c1 t2 t3
                   (h2
                      by (aux . . . H9)
P (CHead c1 (Bind b) t2) t4 t5
                   end of h2
                   by (H4 . . . H8 h1 . . . H9 h2)
P c1 (THead (Bind b) t2 t4) (THead (Bind b) t2 t5)
                case ty3_appl c1:C t2:T t3:T H8:ty3 g c1 t2 t3 t4:T t5:T H9:ty3 g c1 t4 (THead (Bind Abst) t3 t5) 
                   the thesis becomes 
                         P
                           c1
                           THead (Flat Appl) t2 t4
                           THead (Flat Appl) t2 (THead (Bind Abst) t3 t5)
                   (h1by (aux . . . H8) we proved P c1 t2 t3
                   (h2
                      by (aux . . . H9)
P c1 t4 (THead (Bind Abst) t3 t5)
                   end of h2
                   by (H5 . . . H8 h1 . . H9 h2)

                      P
                        c1
                        THead (Flat Appl) t2 t4
                        THead (Flat Appl) t2 (THead (Bind Abst) t3 t5)
                case ty3_cast c1:C t2:T t3:T H8:ty3 g c1 t2 t3 t4:T H9:ty3 g c1 t3 t4 
                   the thesis becomes P c1 (THead (Flat Cast) t3 t2) (THead (Flat Cast) t4 t3)
                   (h1by (aux . . . H8) we proved P c1 t2 t3
                   (h2by (aux . . . H9) we proved P c1 t3 t4
                   by (H6 . . . H8 h1 . H9 h2)
P c1 (THead (Flat Cast) t3 t2) (THead (Flat Cast) t4 t3)
             we proved P c t t1
c:C.t:T.t1:T.(ty3 g c t t1)(P c t t1)
          done
          consider aux
          we proved c:C.t:T.t1:T.(ty3 g c t t1)(P c t t1)
       we proved 
          g:G
            .P:CTTProp
              .c:C
                  .t:T
                    .t1:T
                      .ty3 g c t t1
                        (P c t t1)t2:T.t3:T.(ty3 g c t2 t3)(P c t2 t3)(pc3 c t3 t)(P c t2 t)
                (c:C.n:nat.(P c (TSort n) (TSort (next g n)))
                     (n:nat
                            .c:C
                              .c1:C
                                .t:T
                                  .getl n c (CHead c1 (Bind Abbr) t)
                                    t1:T.(ty3 g c1 t t1)(P c1 t t1)(P c (TLRef n) (lift (S n) O t1))
                          (n:nat
                                 .c:C
                                   .c1:C
                                     .t:T
                                       .getl n c (CHead c1 (Bind Abst) t)
                                         t1:T.(ty3 g c1 t t1)(P c1 t t1)(P c (TLRef n) (lift (S n) O t))
                               (c:C
                                      .t:T
                                        .t1:T
                                          .ty3 g c t t1
                                            (P c t t1
                                                 b:B
                                                      .t2:T
                                                        .t3:T
                                                          .ty3 g (CHead c (Bind b) t) t2 t3
                                                            (P (CHead c (Bind b) t) t2 t3
                                                                 P c (THead (Bind b) t t2) (THead (Bind b) t t3)))
                                    (c:C
                                           .t:T
                                             .t1:T
                                               .ty3 g c t t1
                                                 (P c t t1
                                                      t2:T
                                                           .t3:T
                                                             .ty3 g c t2 (THead (Bind Abst) t1 t3)
                                                               (P c t2 (THead (Bind Abst) t1 t3)
                                                                    (P
                                                                         c
                                                                         THead (Flat Appl) t t2
                                                                         THead (Flat Appl) t (THead (Bind Abst) t1 t3))))
                                         (c:C
                                                .t:T
                                                  .t1:T
                                                    .ty3 g c t t1
                                                      (P c t t1
                                                           t2:T
                                                                .ty3 g c t1 t2
                                                                  (P c t1 t2)(P c (THead (Flat Cast) t1 t) (THead (Flat Cast) t2 t1)))
                                              c:C.t:T.t1:T.(ty3 g c t t1)(P c t t1)))))))