Intervals

Intervals

This section contains :gbbopen-core entities that pertain to intervals. An interval [a,b] is the set of real numbers between the start value of the interval, a, and the end value, b, inclusive. The interval [x,x] represents the single point x.

An interval is represented as either a cons, a two-element list, or a two-element array containing the start and end values of the interval. So, a representation for the interval [0,100] can be created as any of the following:

• (cons 0 100)
• (list 0 100)
• (vector 0 100)

Intervals also include the unbounded intervals:

• (-∞,∞)   (provided as the constant infinite-interval)
• (-∞,x]   (for example, (make-interval x infinity))
• [x,∞)   (for example, (make-interval -infinity x))

It is an error for the start value of an interval to be greater than the end value.

Entities

• *coerce-contracted-interval-rationals-to-floats*
• copy-interval
• expand-interval
• expand-point
• infinite-interval
• interval-end
• interval-start
• interval-values
• make-interval
• nexpand-interval
• nshift-interval
• shift-interval

Intervals