Oracle 21c

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create type a as object(
  a  integer
);
with b(c) as (
  select a(2) from dual
)
select b.c.a
from   b b


C.A


2


with b(c) as (
  select a(2) from dual
)
select b.c.a
from   b
ORA-00904: "B"."C"."A": invalid identifier