DRUG CLASS AND MECHANISM: Rosuvastatin is an oral drug for lowering blood cholesterol levels. It belongs to a class of drugs called HMG-CoA reductase inhibitors, more commonly referred to as  statins ..RUG CLASS AND MECHANISM: Rosuvastatin is an oral drug for lowering blood cholesterol levels. It belongs to a class of drugs called HMG-CoA reductase inhibitors, more commonly referred to as  statins ..
Natural numbers are naturally used for counting apples (and other things) so they are sometimes called counting numbers. Even some animals other than humans can count and add, so they must be natural. Minus two apples isn't very natural so negative numbers are not included.
In the area of mathematics called set theory, a special case of the von Neumann ordinal construction defines the natural numbers as follows: 1  Set 0 = { }, the empty set, 2  Define S(a) = a  3  {a} for every set a. 4  By the axiom of infinity, there exists a set which contains 0 and is closed under the successor function.