MODULE m;

TYPE
	Base = RECORD END;
	Derived1 = RECORD(Base) field1: INTEGER END;
	Derived2 = RECORD(Derived1) field2: INTEGER END;
VAR
	pb: POINTER TO Base;
	pd1: POINTER TO Derived1;
	pd2: POINTER TO Derived2;
	b: BOOLEAN;
BEGIN 
    NEW(pd2);
    pb := pd2;
    pd1 := pd2;
    b := pb IS Derived1;
    b := pb IS Derived2;
    b := pd1 IS Derived2
END m.