Class (redirected from Class c drugs)

class, in taxonomy: see classification.

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class

(1) In object technology, a user-defined data type that defines a collection of objects that share the same characteristics. An object, or class member, is one instance of the class. Concrete classes are designed to be instantiated. Abstract classes are designed to pass on characteristics through inheritance. See instantiate.

(2) In networking, a categorization of a packet based on attributes such as protocol, port and source and destination addresses.

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class

1. (in Marxist theory) a group of persons sharing the same relationship to the means of production

2. 

a. a group of pupils or students who are taught and study together

b. a meeting of a group of students for tuition

3. Chiefly US a group of students who graduated in a specified year

4. Brit a grade of attainment in a university honours degree

5. 

a. outstanding speed and stamina in a racehorse

b. (as modifier): the class horse in the race

6. Biology any of the taxonomic groups into which a phylum is divided and which contains one or more orders. Amphibia, Reptilia, and Mammalia are three classes of phylum Chordata

7. Maths Logic

a. another name for set

b. proper class a class which cannot itself be a member of other classes

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class [klas]

(computer science)

In object-oriented programming, a description of the structure and operations of an object. A new class is defined by stating how it differs from an existing class. The new (more specific) class is said to inherit from the original (general) class and is referred to as a subclass of the original class. The original class is referred to as the superclass of the new class.

(mathematics)

A set that consists of all the sets having a specified property.

The class of a plane curve is the largest number of tangents that can be drawn to the curve from any point in the plane that is not on the curve.

(statistics)

A collection of adjacent values of a random variable.

(systematics)

A taxonomic category ranking above the order and below the phylum or division.

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class

As applied to concrete: a characterization according to some quality (such as compressive strength) or usage.

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1.	(programming)	class - The prototype for an object in an object-oriented language; analogous to a derived type in a procedural language. A class may also be considered to be a set of objects which share a common structure and behaviour. The structure of a class is determined by the class variables which represent the state of an object of that class and the behaviour is given by a set of methods associated with the class. Classes are related in a class hierarchy. One class may be a specialisation (a "subclass") of another (one of its "superclasses") or it may be composed of other classes or it may use other classes in a client-server relationship. A class may be an abstract class or a concrete class. See also signature.
2.	(programming)	class - See type class.
3.	(networking)	class - One of three types of Internet addresses distinguished by their most significant bits.
4.	(language)	class - A language developed by the Andrew Project. It was one of the first attempts to add object-oriented features to C.

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Class 

the grouping of farm animals in classes established by judging the animals in terms of a set of features.

The rules for assigning animals to a particular class are determined by the directions for the valuation of various species developed by the Ministry of Agriculture of the USSR. The indexes of ratable features for first class (liveweight, exterior, productivity) are the basic ones and correspond to the requirements for the registration of the animals in the State Herdbook. More valuable animals are classed as elite and elite record; less valuable animals are assigned to second class, third class, and fourth class. Animals in breeding stock that fall outside these classes are culled from the herd.

The class is an index of the breeding value and economic worth of livestock; according to the class, prices are established and the animals are set aside either for breeding or for use.

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Class 

in biology, one of the higher taxonomic categories of animals and plants. A class embraces related orders of animals or plants. The class Mammalia comprises many orders, including the orders Rodentia, Insectivora, and Carnivora. In turn, classes with members that are similar in their general structure and have common ancestors are grouped in a phylum. For example, the phylum Chordata comprises the classes Pisces, Amphibia, Reptilia, Mammalia, and others. The classes Monocotyledonae and Dicotyledonae constitute the phylum Angiospermae. The concept of class was introduced into taxonomy by the French botanist J. de Tournefort and was subsequently adopted by C. Linnaeus in his Systema naturae (1735).

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Class 

(in logic), a concept expressing an aggregate (set) of objects satisfying some condition or criterion (a distinction is sometimes made between the concepts “class” and “set”; this is connected with special problems in set theory); for these objects, it is said that they are elements of the (given) class (the relation of belonging to a class is usually denoted by the symbol ∊; the notation a ∊ A is read “a is an element of the class Ā”). It is assumed that for every property (or concept of a property) it is possible to find the class of objects having that property; for example, the class of all even numbers corresponds to the property of being an even number.

The class corresponding to a certain property may consist of any finite number of objects (finite classes are often given by an enumeration of their objects—by a list of their names); it may be infinite (for example, the aforementioned class of all even numbers); or it may be empty (that is, it does not contain any elements at all; the empty class is usually denoted by ʌ or Ø). A class consisting of only one element is called unitary or singular (Aristotle did not introduce singular or empty sets into the construction of his system of syllogisms). In contrast to the empty class is the universal class (denoted by V), specifying the range of the objects under study and composed of all objects under consideration in the object domain. Classes are usually depicted geometrically by figures bounded by simple closed curves (for example, circles in the plane).

We now consider operations upon classes and relations between them. There are several operations upon classes. The intersection of classes A and B is the class (usually denoted by A ∩ B) consisting of all those, and only those, elements contained in both class A and class B; the union of classes A and B is the class A ∪ B consisting of all those, and only those, elements contained in at least one of the classes A or B; the complement of a class A is the class Ā consisting of all those, and only those, objects of the universal class that do not belong to the class A. Relations between (two arbitrary) classes include identity (coincidence), inclusion (one set is part of [a subclass of] another), partial coincidence (when the classes have at least one common element), and exclusion (when they have no common elements). The properties of operations upon classes and relations between classes are studied in the logic of classes.

REFERENCES

Hubert, D., and W. Ackerman. Osnovy teoreticheskoi logiki. Moscow, 1947. (Translated from German.)
Tarski, A. Vvedenie v Logiku i metodologiiu deduktivnykh nauk. Moscow, 1948. (Translated from English.)
Ianovskaia, S. A. “Logika klassov.” In Filosofskaia entsiklopediia, vol. 3. Moscow, 1964.
Kuzichev, A. S. Diagrammy Venna. Moscow, 1968.
Mendelson, E. Vvedenie v matematicheskuiu logiku. Moscow, 1971. (Translated from English.)

A. S. KUZICHEV