2.7.1 Syntax

The upper bound of interval   i is denoted by while denotes the lower bound:  

The width of an interval is the difference between the upper and lower bound, and is denoted by for the interval i:  

Every interval has non-negative width:

Most intervals have positive width, but an interval could have zero width if it represents a particular real number which happens to coincide with a floating point number. A real number is contained in an interval if that interval can represent the real number:

The set of numbers within an interval i is denoted by :  

Jeff Tupper

March 1996