A negative number is a real number that is less than zero and is typically represented with a minus sign (−) before the number. Negative numbers extend the concept of integers and real numbers into values below zero, enabling the representation of debt, temperatures below freezing, elevations below sea level, and losses in various contexts. […]
In algebra, the 3x + 1 semigroup is a special subsemigroup of the multiplicative semigroup of all positive rational numbers. The elements of a generating set of this semigroup are related to the sequence of numbers involved in the still open Collatz conjecture or the “3x + 1 problem”. The 3x + 1 semigroup has been used to prove a weaker form of the Collatz conjecture. In fact, it