conjunto dos números inteiros

Belong to the set of integers, negative numbers and also the set of natural numbers, ie positive numbers.

The positive numbers to negative numbers are opposite and opposing negative to positive.
Their representation is made by the capital letter Z.

Z = {..., -4, -3, -2, -1, 0, +1, +2, +3, ...}

Remarks: negative numbers are always accompanied by a negative sign
(-) (In front) and positive are accompanied by a positive sign (+) or no sign. Zero is not positive nor negative.

♦ Whole non - null
Are the integers, less zero.
In its representation should put * next to the Z.
Z * = {... -3, -2, -1, 1, 2, 3, ...}

♦ positive integers not
Are negative numbers including zero.
In its representation should be placed - side to Z.
Z_ = {... -3, -2, -1, 0}

♦ not positive integers and non - null
Are integers from the set Z_ excluding zero.
In its representation we put _ and * next to the Z.
Z * _ = {... -3, -2, -1}

♦ non-negative integers
Are positive numbers including zero.
In its representation should put the + side of the Z.
Z + = {0,1, 2, 3, 4, ...}
The set Z + is equal to the set of N

♦ non-negative integers and non - null
Are the numbers of the set Z +, excluding zero.
In its representation should put the + and * next to the Z.
+ Z * = {1, 2, 3, 4, ...}
The set Z + * is set equal to N *