Negative and Non Numbers

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Being negative or non-negative is a property of a number which is real, or a member of a subset of real numbers such as rational and integer numbers. A negative number is one that is less than zero, such as ¿{sqrt{2}}, ¿1.414, ¿1. A positive number (e.g., positive real number, positive rational number, positive integer) is one that is greater than zero, such as {sqrt{2}}, 1.414, 1. Zero itself is neither positive nor negative. The non-negative numbers are the numbers that are not negative (they are positive or zero). The non-positive numbers are the numbers that are not positive (they are negative or zero). In the context of complex numbers, positive implies real, but for clarity one may say "positive real number".