Instead of using modular addition, we could use the bitwise exclusive-OR ( \oplus ) operation so that \begin{equation*} N_l=(N_{l-i})\oplus (N_{l-j}) \end{equation*} where the bitwise action of \oplus means that if N_{l-i}=N_{l-j} the result is 0 whereas if N_{l-i}\ne N_{l-j} the result is 1 . As an example, consider the case where N_{l-i}=6 and N_{l-j}=11 . The first one has a bit representation (using 4 bits only) which reads 0110 whereas the second number is 1011 . Employing the \oplus operator yields 1101 , or 2^3+2^2+2^0=13 .
In Fortran90, the bitwise \oplus operation is coded through the intrinsic function \mathrm{IEOR}(m,n) where m and n are the input numbers, while in C it is given by m\wedge n .