I'm not sure how to describe this, so I came up with a rough diagram/scenario as an example:

<http://imageshack.us/photo/my-images/703/tuc8.png/>

Say for example if a company has employees who are either part/full time, which are further branched into the types of employees(sales, admin...etc). How would I express this form of generalization? Is the way I express it in the diagram correct.

I tried looking for similar diagrams/scenarios in google, but couldn't find anything.
For now, lets say part time and full time classes have to be defined as a class/object(ie. the employment type cannot be specified as a string....)