Integer If the domain is restricted to then each and every member of has one and only one corresponding member of N and by the definition of cardinal equality the two sets have equal cardinality. Integer An integer (from the Latin "integer" meaning "whole") is a number that can be written without a fractional component. For example, 21, 4, 0, and −2048 are integers, while 9.75, , and are not. The set of integers consists of zero (), the positive natural numbers (, , , …), also called "whole numbers" or "counting numbers", and their additive inverses (the negative integers, i.e.,
Computable number the machine's table – is being used to define what is a potentially-"infinite" string of decimal digits. This is however not the modern definition which only requires the result be accurate to within any given accuracy. The informal definition above is subject to a rounding problem called the table-maker's dilemma whereas the modern definition is not. A real number "a" is computable if it can be approximated by some computable function formula_1 in the following manner: given any positive integer "n", the function produces an integer "f"("n") such that: There are two similar definitions that are equivalent: There is another