-- https://docs.oracle.com/en/database/oracle/oracle-database/23/lnpls/plsql-language-fundamentals.html
DECLARE
  acct_id INTEGER(4) NOT NULL := 9999;
  a NATURALN                  := 9999;
  b POSITIVEN                 := 9999;
  c SIMPLE_INTEGER            := 9999;
BEGIN
  NULL;
END;
/