Question

Which of the following sets is not finite?

Answer 1

$\{x|x\in\mathbb{N}\ \wedge\ n < 10\}=\{0;\ 1;\ 2;\ 3;\ 4;\ 5;\ 6;\ 7;\ 8;\ 9\}-FINITE\\\\\{x|x\in\mathbb{Z}\ \wedge\ 0 < x < 10\}=\{1;\ 2;\ 3;\ 4;\ 5;\ 6;\ 7;\ 8;\ 9\}-FINITE\\\\\{x|x\in\mathbb{Z}\ \wedge\ x < 0\}=\{...;-4;-3;-2;-1\}=\mathbb{Z}^--NOT\ FINITE$