An interval is a set of numbers between upper and lower bound. To create an interval, type e.g.
2 < x < 3 in Input Bar. Interval in previous example is open. You can also define closed (
2 ≤ x ≤ 3) and semi-closed (
2 ≤ x < 3) intervals.
To determine whether number c belongs to interval r type
r(c) into the Input Bar, the result will be a Boolean value. Generalization of intervals are Inequalities.
Commands for intervals
- Min, Max, Midpoint for an interval with lower bound a and upper bound b return numbers a, b and respectively. The result doesn't depend on whether the interval is open, closed or semi-closed.
- Point returns a moveable point whose x-coordinate belongs to the interval and y-coordinate is 0.
- PointIn returns a moveable point whose x-coordinate belongs to the interval and y-coordinate may be changed arbitrarily.