If we then let "N" be the subgroup of "F" generated by all conjugates "x"−1"Rx" of "R", then it follows by definition that every element of "N" is a finite product "x"1−1"r"1"x"1 ... "xm"−1"rm" "xm" of members of such conjugates. It follows that each element of "N", when considered as a product in D8, will also evaluate to 1; and thus that "N" is a normal subgroup of "F". Thus D8 is isomorphic to the quotient group . We then say that D8 has presentation