Anonymous wrote:If there is a class Z extending Y which extends X and so on so forth till A, how should we draw the diagram to depict the relationship in class diagram?
I'm sure there should be a way to draw it without making all 26 class boxes..
You will need to illustrate all the classes and their relations if that is what you're modelling. There is no "way" to simplify this model without losing information. In practicality, if you encounter such a scenario, I would consider revisiting the design.
But as Lilian requested, if you find a reference indicating a method of modelling this idea, let us know.