Function nesting issue

i have 2 functions, naming a and b, both outputing a resultset(cursor)
and a integer.
a calls b

a:
CREATE OR REPLACE FUNCTION "public"."t_outer" (out o_rs
"pg_catalog"."refcursor", out o_i integer) RETURNS record AS
...
select t_inner(o_rs, o_i);
...

b:
CREATE OR REPLACE FUNCTION "public"."t_inner" (out o_rs
"pg_catalog"."refcursor", out o_i integer) RETURNS record AS
...

Compilation is ok, but when i call a, it says:
ERROR: function b(refcursor, integer) does not exist
No function matches the given name and argument types. You might need
to add explicit type casts.

So, my question is whether postgreSQL supporting this type of nesting?

thanks. if this is an old question, please forgive me.

regards

--
Alferd.