An approximation can be abstract.Logical formLearned from4 sentences. A (pipeline model) can be abstract.Logical formLearned from4 sentences. An abstract model may undergo a refinement.Logical formLearned from4 sentences. Pieces can be abstract.Logical formLearned from4 sentences. Characterizations can be abstract.Logical formLearned from4 sentences. An encoding can be abstract.Logical formLearned from4 sentences. Privileges can be abstract.Logical formLearned from4 sentences. An abstract model can be for presence.Logical formLearned from4 sentences. Principals can be abstract.Logical formLearned from4 sentences. An (algebra textbook) can be abstract.Logical formLearned from4 sentences. An injustice can be abstract.Logical formLearned from4 sentences. An observation can be abstract.Logical formLearned from4 sentences. Abstract objects can be acausal.Logical formLearned from4 sentences. Accounts can be abstract.Logical formLearned from4 sentences. Abstract expressionists may pertain-to 1950s.Logical formLearned from4 sentences.