An operator is applied to a signal one element at a time. For example, the operator ~ stands for logical ``not''. Thus if
foo = 0;1;0;1;...then
~foo = 1;0;1;0;...
That is, it is the result of applying logical ``not'' to each element of the sequence. Similarly, & stands for logical ``and''. Thus, if
foo = 0;1;0;1;... and bar = 0;0;1;1;...then
foo & bar = 0;0;0;1;...