Abstract
This paper describes some aspects of a Requirements Modeling Language (RML) which can be used in the initial phases of software development. RML is based on the idea that a requirements specification should embody a
conceptual world model and that the language for expressing it should provide facilities for organizing and abstracting details, yet at the same time have qualities such as precision, consistency and clarity.
RML has a number of novel features including assertion classes, the treatment of time and various abbreviation techniques, all integrated into one uniform object-oriented framework. The precise semantics of these and other features are provided in this paper by relating RML to a logic involving time. This demonstrates that a language can offer highly structured and convenient mechanisms for requirements specifications while having solid mathematical underpinnings.