An abstract class may define methods.Logical formLearned from2 sentences. Receivers can be abstract.Logical formLearned from2 sentences. An abstract number may undergo an insertion.Logical formLearned from2 sentences. An abstract number can be raw.Logical formLearned from2 sentences. A line can be for insertion of an abstract number.Logical formLearned from2 sentences. A derived type can be abstract.Logical formLearned from2 sentences. An abstract type may have operations.Logical formLearned from2 sentences. A part can be abstract.Logical formLearned from2 sentences. A (type iterator) can be abstract.Logical formLearned from2 sentences. A function can be abstract.Logical formLearned from2 sentences. A type can be abstract.Logical formLearned from2 sentences. A (state machine theory) can be abstract.Logical formLearned from2 sentences. A (layout specification) can be abstract.Logical formLearned from2 sentences. (Classification schemes) can be abstract.Logical formLearned from2 sentences. Persons may view abstract (data types).Logical formLearned from2 sentences.