boolean 'not' t-sql operative 'bit' datatype?

trying perform unparalleled boolean operation, appears underneath ms sql server 2005, following retard does work

declare @myboolean bit;
set @myboolean = 0;
set @myboolean = @myboolean;
select @myboolean;

instead, i am removing some-more successful with

declare @myboolean bit;
set @myboolean = 0;
set @myboolean = 1 - @myboolean;
select @myboolean;

yet, looks bit crippled proceed demonstrate something rudimentary negation.

am i blank something?