Enumerative definition

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An enumerative definition of a concept or term is a special type of extensional definition that gives an explicit and exhaustive listing of all the objects that fall under the concept or term in question. Enumerative definitions are only possible for finite sets and only practical for relatively small sets.

An example of an enumerative definition for the set

extant monotreme species

(for which the intensional definition is species of currently-living mammals that lay eggs ) would be

platypuses
echidnae:
short-beaked echidna
long-beaked echidnae:
Sir David's long-beaked echidna
eastern long-beaked echidna
western long-beaked echidna

See also


Related Research Articles

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In any of several studies that treat the use of signs—for example, in linguistics, logic, mathematics, semantics, and semiotics—the extension of a concept, idea, or sign consists of the things to which it applies, in contrast with its comprehension or intension, which consists very roughly of the ideas, properties, or corresponding signs that are implied or suggested by the concept in question.

Echidna Family of mammals

Echidnas, sometimes known as spiny anteaters, belong to the family Tachyglossidae in the monotreme order of egg-laying mammals. The four extant species of echidnas and the platypus are the only living mammals that lay eggs and the only surviving members of the order Monotremata. The diet of some species consists of ants and termites, but they are not closely related to the true anteaters of the Americas, which are xenarthrans. Echidnas live in Australia and New Guinea.

An enumeration is a complete, ordered listing of all the items in a collection. The term is commonly used in mathematics and computer science to refer to a listing of all of the elements of a set. The precise requirements for an enumeration depend on the discipline of study and the context of a given problem.

Insectivore Organism which eats insects

An insectivore is a carnivorous plant or animal that eats insects. An alternative term is entomophage, which also refers to the human practice of eating insects.

In computability theory, a set S of natural numbers is called computably enumerable (c.e.), recursively enumerable (r.e.), semidecidable, partially decidable, listable, provable or Turing-recognizable if:

Lorentz National Park Indonesian national park

Lorentz National Park is a national park located in Papua, Indonesia, in the southwest of western New Guinea. With an area of 25,056 km2 (9,674 mi2), it is the largest national park in southeast Asia. In 1999 Lorentz was declared a World Heritage Site by UNESCO.

Long-beaked echidna Genus of monotremes

The long-beaked echidnas make up one of the two extant genera of echidnas, spiny monotremes that live in New Guinea; the other being the short-beaked echidna. There are three living species and two extinct species in this genus. The extinct species were present in Australia. Echidnas are one of the two types of mammals that lay eggs, the other being the platypus. The echidnas retain reptilian features such as egg-laying but display mammalian features such as fur and lactation.

Electroreception

Electroreception or electroception is the biological ability to perceive natural electrical stimuli. It has been observed almost exclusively in aquatic or amphibious animals since water is a much better conductor of electricity than air. The known exceptions are the monotremes (echidnas and platypuses), cockroaches, and bees. Electroreception is used in electrolocation and for electrocommunication.

Short-beaked echidna Spiny furred egg-laying mammal from Australia

The short-beaked echidna is one of four living species of echidna and the only member of the genus Tachyglossus. It is covered in fur and spines and has a distinctive snout and a specialized tongue, which it uses to catch its insect prey at a great speed. Like the other extant monotremes, the short-beaked echidna lays eggs; the monotremes are the only living group of mammals to do so.

Western long-beaked echidna Species of monotreme

The western long-beaked echidna is one of the four extant echidnas and one of three species of Zaglossus that occur in New Guinea. Originally described as Tachyglossus bruijnii, this is the type species of Zaglossus.

The echidna flea is the larger of two species of flea commonly found on the short-beaked echidna. It is monotypic, that is, the only species in the genus. This flea reaches 4 millimetres in length and has been claimed to be the world's largest flea. This statement is in error as the world's largest flea is known to be the mountain beaver flea which can be as large as 12 millimetres in length.

Sir Davids long-beaked echidna Species of monotreme

Sir David's long-beaked echidna, also known as Attenborough's long-beaked echidna or the Cyclops long-beaked echidna, is one of the three species from the genus Zaglossus that occurs in New Guinea. It is named in honour of Sir David Attenborough, the eminent naturalist. It lives in the Cyclops Mountains, which are near the cities of Sentani and Jayapura in the Indonesian province of Papua.

Eastern long-beaked echidna Species of monotreme

The eastern long-beaked echidna, also known as Barton's long-beaked echidna, is one of three species from the genus Zaglossus to occur in New Guinea. It is found mainly in the eastern half at elevations between 2,000 and 3,000 metres.

<i>Megalibgwilia</i> Extinct genus of monotremes

Megalibgwilia is a genus of echidna known only from Australian fossils that incorporates the oldest-known echidna species. It is also the only extinct echidna genus. The genus ranged from the Miocene until the late Pleistocene, becoming extinct about 50,000 years ago. Megalibgwilia species were more widespread in warmer and moist climates. The extinction can be attributed to increasing aridification in Southern Australia.

<i>Zaglossus hacketti</i> Extinct species of monotreme

Zaglossus hacketti is an extinct species of long-beaked echidna from Western Australia that is dated to the Pleistocene. It is known only from a few bones. It was about 1 m long and probably weighed about 30 kg (66 lb). This makes it the largest monotreme known to have ever lived. Due to the lack of cranial material, placement of Z. hacketti into the modern long-beaked echidna genus Zaglossus is uncertain.

Monotreme Order of egg-laying mammals

Monotremes are one of the three main groups of living mammals, along with placentals (Eutheria) and marsupials (Metatheria). The monotremes are typified by structural differences in their brains, jaws, digestive tract, reproductive tract, and other body parts compared to the more common mammalian types. In addition, they lay eggs rather than bearing live young, but, like all mammals, the female monotremes nurse their young with milk.

Vermivore

Vermivore is a zoological term for animals that eat worms. Animals with such a diet are known to be vermivorous. Some definitions are less exclusive with respect to the diet, but limit the definition to particular animals, e.g. "Feeding on worms or insect vermin. Used of a bird."

Yinotheria Subclass of mammals

Yinotheria is a proposed basal subclass clade of crown mammals that contains a few fossils of the Mesozoic and the extant monotremes. Today, there are only five surviving species, which live in Australia and New Guinea, but fossils have been found in England, China, Russia, Madagascar and Argentina. The surviving species consist of the platypus and four species of echidna. Contrary to other known crown mammals, they retained postdentary bones as shown by the presence of a postdentary trough. The extant members (monotremes) developed the mammalian middle ear independently.

In logic, philosophy, and mathematics, extensional and intensional definitions are two key ways in which the objects, concepts, or referents a term refers to can be defined. They give meaning or denotation to a term.