Definition:Interval/Notation/Wirth

Definition
The notation used on this site to denote a real interval is a fairly recent innovation, and was introduced by C. A. R. Hoare and Lyle Ramshaw:

The term Hoare-Ramshaw notation has consequently been coined by ProofWiki.

This double dots notation has a worthy precedent in the sphere of computer languages.

For example, Pascal uses the same notation for a closed interval.