DECLARE

    TYPE nested_typ IS TABLE OF NUMBER;

    nt1 nested_typ := nested_typ(1,2,3); nt2 nested_typ := nested_typ(3,2,1);

    nt3 nested_typ := nested_typ(2,3,1,3); nt4 nested_typ := nested_typ(1,2,4);

   PROCEDURE testify (truth BOOLEAN := NULL, quantity NUMBER := NULL) IS

    BEGIN

        IF truth IS NOT NULL THEN

            DBMS_OUTPUT.PUT_LINE (

            CASE truth

                WHEN TRUE THEN 'True'

                WHEN FALSE THEN 'False'

            END);

        END IF;

        IF quantity IS NOT NULL THEN DBMS_OUTPUT.PUT_LINE(quantity); END IF;

  END;

BEGIN

    testify(truth => (nt1 IN (nt2, nt3, nt4)));        -- 条件

    testify(truth => (nt1 SUBMULTISET OF nt3));      -- 条件

testify(truth => (nt1 NOT SUBMULTISET OF nt4));  -- 条件

--测试集合成员的个数

    testify(truth => (4 MEMBER OF nt1));             -- 条件

    testify(truth => (nt3 IS A SET));                -- 条件

    testify(truth => (nt3 IS NOT A SET));            -- 条件

    testify(truth => (nt1 IS EMPTY));                -- 条件

    -- cardinality返回嵌套表中元素的个数

    testify(quantity => (CARDINALITY(nt3)));         -- 函数

    testify(quantity => (CARDINALITY(SET(nt3))));    -- 2个函数

END;