Boolean operations "not," "and" and "or" are similar to arithmetic operations of negation, multiplication and addition. For arithmetic, we have rules saying which operations are performed first. For example, multiplication is performed before addition. Boolean algebra is less common and there is a wider variety of conventions concerning which operation is performed first. Therefore I am asking you to make this expression unambiguous by inserting some parentheses.
OK, in fact there is a more-or-less standard order of operations for Boolean algebra, though it is probably still less standard than for arithmetic. However, since your expression does not have any parentheses, I somehow doubt that this standard order can be used here. Before I spend time on analyzing the expression, I'd like to be sure that the expression is the correct one.
Now, you can't mathematically solve the problem of which operation is performed first. This is a matter of definition. To find this definition, you have to go to the source from which this problem comes.
Also, to repeat, your links don't work.