*a*and

*b*be enumerable values (more specifically, they are members of a totally ordered set) such that

*a*<

*b*. Then for endpoints

*a*and

*b,*

(

*a,b*) is all values*> a*and*<> [**a,b*] is all values >=*a*and <=*b*(*a,b*] is all values >*a*and <=*b*[*a,b*) is all values >=*a*and <*b***References**[1] Interval (mathematics), Wikipedia, 2008 [2] Set-builder & Interval Notation, Oswego City School District Regents Exam Prep Center, 2008 [3] Totally Ordered Set, Wolfram MathWorld, 2008