DEFINITION getl_drop_conf_lt()
TYPE =
       b:B
         .c:C
           .c0:C
             .u:T
               .i:nat
                 .getl i c (CHead c0 (Bind b) u)
                   e:C
                        .h:nat
                          .d:nat
                            .drop h (S (plus i d)) c e
                              (ex3_2
                                   T
                                   C
                                   λv:T.λ:C.eq T u (lift h d v)
                                   λv:T.λe0:C.getl i e (CHead e0 (Bind b) v)
                                   λ:T.λe0:C.drop h d c0 e0)
BODY =
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