-- https://docs.oracle.com/en/database/oracle/oracle-database/23/lnpls/plsql-language-fundamentals.html
<<echo>>
DECLARE
  x  NUMBER := 5;

  PROCEDURE echo AS
    x  NUMBER := 0;
  BEGIN
    DBMS_OUTPUT.PUT_LINE('x = ' || x);
    DBMS_OUTPUT.PUT_LINE('echo.x = ' || echo.x);
  END;

BEGIN
  echo;
END;
/