Nim (which is inspired in part by Pascal and Ada) uses “a..b” to denote a closed interval and a..<b to denote an interval half-open on the right. The language

Nim (which is inspired in part by Pascal and Ada) uses “a..b” to denote a closed interval and a..<b to denote an interval half-open on the right. The language is flexible enough to also let you define a<..b and a<.<b to complete the quartet, but I don’t know if anyone who ever did.