48     assert(!(p1 == nullptr));  in main()
49     assert(!(nullptr == p1));  in main()
50     assert(!(p1 < nullptr));  in main()
51     assert( (nullptr < p1));  in main()
52     assert(!(p1 <= nullptr));  in main()
53     assert( (nullptr <= p1));  in main()
54     assert( (p1 > nullptr));  in main()
55     assert(!(nullptr > p1));  in main()
56     assert( (p1 >= nullptr));  in main()
57     assert(!(nullptr >= p1));  in main()
60     assert( (p2 == nullptr));  in main()
61     assert( (nullptr == p2));  in main()
62     assert(!(p2 < nullptr));  in main()
63     assert(!(nullptr < p2));  in main()
64     assert( (p2 <= nullptr));  in main()
65     assert( (nullptr <= p2));  in main()
66     assert(!(p2 > nullptr));  in main()
67     assert(!(nullptr > p2));  in main()
68     assert( (p2 >= nullptr));  in main()
69     assert( (nullptr >= p2));  in main()