<Tr> <Td> 2 = │ ((1, 1, 1), (1, 1, 2), (1, 2, 1), (1, 2, 2), (2, 1, 1), (2, 1, 2), (2, 2, 1), (2, 2, 2)) │ = 8 </Td> <Td> There are eight 3 - tuples from a two - element set . </Td> </Tr> <Tr> <Td> 3 = │ ((1, 1), (1, 2), (1, 3), (2, 1), (2, 2), (2, 3), (3, 1), (3, 2), (3, 3)) │ = 9 </Td> <Td> There are nine 2 - tuples from a three - element set . </Td> </Tr> <Tr> <Td> 4 = │ ((1), (2), (3), (4)) │ = 4 </Td> <Td> There are four 1 - tuples from a four - element set . </Td> </Tr> <Tr> <Td> 5 = │ (()) │ = 1 </Td> <Td> There is exactly one 0 - tuple . </Td> </Tr>

For all real numbers x the result of x 2 is a positive number