Intervals

An interval is a to set of real numbers between two given points: a and b, which are called ends of the interval.

Open Interval

An open interval, (a, b), is the set of all real numbers greater than a and smaller than b.

(a, b) = {x PerteneceSet of Real Numbers/ a < x < b}

Open Interval

Closed Interval

A closed interval, [a, b], is the set of all real numbers greater than or equal to a and less than or equal to b.

[a, b] = {x Pertenece Set of Real Numbers / a ≤ x ≤ b}

Closed Interval

Half-Closed Intervals

(a, b] = {x Pertenece Set of Real Numbers / a < x ≤ b}

Half-Closed Intervals

[a, b) = {x Pertenece Set of Real Numbers/ a ≤ x < b}

Half-Closed Intervals

Half-closed intervals are also called half-open intervals.

When there are a set of points formed by two or more of these intervals, the sign Unión (Union) is used between them.