<Tr> <Th> </Th> <Td> Unneeded </Td> <Td> Required </Td> <Td> Required </Td> <Td> Unneeded </Td> <Td> Unneeded </Td> </Tr> <Tr> <Th> Groupoid </Th> <Td> Unneeded </Td> <Td> Required </Td> <Td> Required </Td> <Td> Required </Td> <Td> Unneeded </Td> </Tr> <Tr> <Th> Magma </Th> <Td> Required </Td> <Td> Unneeded </Td> <Td> Unneeded </Td> <Td> Unneeded </Td> <Td> Unneeded </Td> </Tr> <Tr> <Th> Quasigroup </Th> <Td> Required </Td> <Td> Unneeded </Td> <Td> Unneeded </Td> <Td> Required </Td> <Td> Unneeded </Td> </Tr>

Example of monoid which is not a group