A decidable constraint diagram reasoning system

Constraint diagrams are a visual notation designed for use by software engineers to formally specify information systems. In this paper we formalize a fragment of the constraint diagram language. A set of reasoning rules are defined and we prove that this set is both sound and complete. Given constraint diagrams D_1 and D_2 such that D_2 is a semantic consequence of D_1, to prove completeness we construct a proof of D_2 from D_1. A decision procedure can be extracted from this proof construction process and it follows that the system is decidabl