OCL Visualization - A Reality Check

Visual representations, particularly in the context of a visual paradigm such as UML, have many attractions. At OCL 2018, vOCL was presented with the well intentioned goal of making hard-to-read textual OCL more accessible within diagrams. The approach as presented was unfortunately technically unsound. This paper repairs the technical problems in the vOCL approach, and contrasts it with four other approaches.