The Triangulation Calculus

The Duration Calculus is an important tool in the tool bag of the real-time systems engineer. The distinguishing and powerful feature of the Duration Calculus is interpretations are given with respect to (open) intervals of the real-line. This allows properties of intervals to be specified and reasoned about. In an attempt to understand the relationship between the logic underlying the Duration Calculus and the domain over which it works, we have produced the Triangulation Calculus which (we claim) does for plane triangles what the Duration Calculus does for intervals. The paper is very closely structured along the lines of [CRH93]. Readers familiar with that paper will recognize this, and have no problem making the translation.