How do I call multiple functions in one trigger?

Hi,

Can I call multiple functions in one trigger?
Something like this:

CREATE TRIGGER match_cond_name_generate
BEFORE INSERT OR UPDATE
ON public.predicate_index
FOR EACH ROW
EXECUTE PROCEDURE public.match_cond_name_generate();
EXECUTE PROCEDURE public.create_predicate_table();

Postgresql won't allow me to do this. Multiple triggers won't guarantee the
order of the operations. Do I have to put everything into one single
function?

Many thanks,

Wei Wang