Lemma reptype_Tarray_JMeq_constr0: forall t gfs t0 n a (v: reptype (nested_field_type t gfs)), legal_nested_field t gfs -> nested_field_type t gfs = Tarray t0 n a -> {v': list (reptype (nested_field_type t (ArraySubsc 0 :: gfs))) | JMeq v v'}.