DEFINITION csubv_getl_conf()
TYPE =
       c1:C
         .c2:C
           .csubv c1 c2
             b1:B
                  .d1:C
                    .v1:T
                      .i:nat
                        .getl i c1 (CHead d1 (Bind b1) v1)
                          ex2_3 B C T λ:B.λd2:C.λ:T.csubv d1 d2 λb2:B.λd2:C.λv2:T.getl i c2 (CHead d2 (Bind b2) v2)
BODY =
Show proof