Logical not: !

!A is true if A is false, and vice versa. For example, the following piece of code finds out the count of items in a list x that don't qualify (assuming that the values of x have the qualify attribute):
>> count = 0;
>> for k = 1 : #x
     if ! x[k].qualify()
          ++count;
     end
   end



oz 2009-12-22