The set of all binary vectors with 12 components forms a field with 2^12 elements containing 000000000000 and another 65*63 elements. Is it possible to partition these elements into 63 subgroups of 65 vectors so that each of them is closed under binary addition (XOR)? For example, if we had 4 components instead of 12, the field contains 0000 and another 3*5 elements, we can partition them as follows: 0000 0001 0010 0011 0100 1000 1100 0101 1010 1111 0110 1011 1101 0111 1001 1110 so that, whenever we add two elements from the same group, we get another from the same group. We have five subgroups closed under XOR that only share the element 0000. Could we do the same with vectors with 12 components? Is there some theorem that governs this property for more components? Thank you!