lConsider the binary relation Òcan be donor forÓ on the domain of blood types: {ÒAÓ, ÒBÓ, ÒABÓ, ÒOÓ}
lAs a list, this relation could be represented
[[ÒAÓ, ÒAÓ], [ÒAÓ, ÒABÓ],
[ÒBÓ, ÒBÓ], [ÒBÓ, ÒABÓ],
[ÒABÓ, ÒABÓ],
[ÒOÓ, ÒAÓ], [ÒOÓ, ÒABÓ], [ÒOÓ, ÒBÓ], [ÒOÓ, ÒOÓ]]
l