Yes, I got the same results:

ll = .t.
llNull = null
=messagebox(ll and llNUll)
=messagebox(ll or llNUll)
=messagebox(not llNull)
ll = .f.
=messagebox(ll and llNUll)
=messagebox(ll or llNUll)
=messagebox(not llNull)

However, try with char fields.

>I must be totally not undertanding the help:
>
>

>Null values persist through logical expressions in most cases. The following table describes the behavior of null values in logical expressions.
>
>Logical expression  Result if x=TRUE  Result if x=FALSE  Result if x=.NULL.
>x AND .NULL.            .NULL.             FALSE               .NULL.
>x OR .NULL.              TRUE              .NULL.              .NULL.
>NOT x                   FALSE              TRUE                .NULL.
>
>