How can you create partitioned shapes?
 

I wish to create Algebraic Specifications in the form proposed by Ian Sommerville in his textbook Software Engineering v7, as on the third page of this chapter: [url]http://www.comp.lancs.ac.uk/computing/resources/IanS/SE7/ElectronicSupplements/AlgebraicSpec.pdf[/url]

I need to create a partitioned shape that allows editing in different regions of the shape, having each region independently expand to fit the text. I have tried grouping shapes with their edges aligned and with various wrapping options set, and I can't find a way to make this happen. Actually, I have had many occasions over the years to need this and can't figure out how to make an easily reusable shape to do it.