I have two main actors in the use case diagram where I am modeling the use cases for the visitors of my project: an admin and a user. A user has to signup and then login in order for him/her to open his/her page while an admin has only to login without doing the signup.
Can I make the admin a generalization of a user since he inherits all use cases of the user except for the signup use case?(ofc he has different use cases as well) If not, then should I show them as actors that have no relation between each other?