Comments on “New General Continuous-Time State−Task Network Formulation for Short-Term Scheduling of Multipurpose Batch Plants” by Christos T. Maravelias and Ignacio E. Grossmann and on “Enhanced Continuous-Time Unit-Specific Event-Based Formulation for Short-Term Scheduling of Multipurpose Batch Processes: Resource Constraints and Mixed Storage Policies” by Stacy L. Janak, Xiaoxia Lin, and Christodoulos A. Floudas