How does 'in' clause works in oracle

Question

select \'true\' from dual where 1 not in (null,1);

when we execute this which will result nothing

what my question is:

is the above

Answer 1

Yes they are.

select something from table where column not in (1,2,3);

is equivalent to

select something from table where column != 1 and column != 2 and column != 3;