The physicist who states a law of nature with the aid of a mathematical formula is abstracting a real feature of a real material world, even if he has to speak of numbers, vectors, tensors, state-functions, or whatever to make the abstraction.
Hamlet 's character is the prevalence of the abstracting and generalizing habit over the practical. He does not want courage, skill, will, or opportunity; but every incident sets him thinking; and it is curious, and at the same time strictly natural, that Hamlet, who all the play seems reason itself, should he impelled, at last, by mere accident to effect his object. I have a smack of Hamlet myself, if I may say so.Samuel Taylor Coleridge
Executable UML is at the next higher layer of abstraction, abstracting away both specific programming languages and decisions about the organization of the software so that a specification built in Executable UML can be deployed in various software environments without change.