This extension allows to merge generalization views quickly into a rectilinear form as shown in the below figures.
Open Extension Manager (Tools > Extension Manager) and select Registry Tab and enter "merge" in search box. You can find this extension and then click install button.
To merge generalizations, select a Class (Superclass) first and then select Tools > Merge Generalizations (Alt+Ctrl+S) or click Merge Generalizations icon in Toolbar.
Licensed under the MIT license (see LICENSE file).