A (service space) can be abstract.Logical formLearned from3 sentences. An eloquence can be abstract.Logical formLearned from3 sentences. A theorist can be abstract.Logical formLearned from3 sentences. Challenges can be abstract.Logical formLearned from3 sentences. A document may define an abstract model.Logical formLearned from3 sentences. An element. can be abstract.Logical formLearned from3 sentences. A model may consist of abstract objects.Logical formLearned from3 sentences. Invocations can be abstract.Logical formLearned from3 sentences. A route can be abstract.Logical formLearned from3 sentences. Trends can be abstract.Logical formLearned from3 sentences. Writing can be abstract.Logical formLearned from3 sentences. (Syntax classes) can be abstract.Logical formLearned from3 sentences. Signals can be abstract.Logical formLearned from3 sentences. (Building blocks) can be abstract.Logical formLearned from3 sentences. Abstract (data types) may undergo implementations.Logical formLearned from3 sentences.