By studying categories and functors, we are not just studying a class of mathematical structures and the morphisms between them ; we are studying the relationships between various classes of mathematical structures.

Most competitions are organized into categories based on sex, age, and weight class.

As a reflection of categories of sexuality so sharply defined by the government and society at large, lesbian subculture developed extremely rigid gender roles between women, particularly among the working class in the U. S. and Canada.

In this paper, he argued for four " fundamental categories " for the theory of grammar: unit, structure, class, and system.

The category of nominal class replaces not only the category of gender, but also the categories of number and case.

These other categories of oppression may include, but are not limited to, oppression based on gender identity, race, social class, perceived attractiveness, sexual orientation, and ability.

Social class ( or simply " class ") is a set of concepts in the social sciences and political theory centered on models of social stratification in which people are grouped into a set of hierarchical social categories.

Today, concepts of social class often assume three general categories: a very wealthy and powerful upper class that owns and controls the means of production ; a middle class of professional workers, small business owners, and low-level managers ; and a lower class, who rely on low-paying wage jobs for their livelihood and often experience poverty.

Conceptually, there is no difference between the latter two categories, and improvements in telescopes can shift previously non-visual binaries into the visual class, as happened with Polaris in 2006.

Even the “ hobbyist ” end of the field can break down into several distinct categories such as: observing deep sky objects, observing the planets, solar observing, lunar observation, and astrophotography of all those class of objects.

After defeating James ' Bubba ' Busceme by sixth round stoppage, Argüello decided to move up in weight class time again, and on November 12, 1982, he tried to become the first world champion in 4 different categories, meeting the heavier and future Hall-of-Famer Aaron Pryor, in what was billed as The Battle of the Champions in Miami, Florida.

The social class of peasant was often broken down into smaller categories.

The most widely used grading system is the International Scale of River Difficulty, where whitewater ( either an individual rapid, or the entire river ) is classed in six categories from class I ( the easiest and safest ) to class VI ( the most difficult and most dangerous ).

The company began concentrating on the Japanese GP's emerging open-wheel " formula car " categories from 1966, winning the " Exhibition " class.

Vineyard classification began in 1730 with vineyards being classified into 3 categories depending on the soil, sun exposure and potential to develop noble rot, botrytis cinerea, first class, second class and third class wines.

From this arrangement, each homophone class can be placed in the above categories.

It is apparent that Medieval society values that class system as the main categories of hierarchical society.

Monogamy is the vice from which the abjectly fearful middle class continue to suffer, whereas the beatnik has the courage to break out of that prison of respectability.

And it is precisely in this poorer economic class that one finds, and has always found, the most racial friction.

Was it supposed, perchance, that A & M ( vocational training, that is ) was quite sufficient for the immigrant class which flooded that part of the New England world in the post-Civil War period, the immigrants having been brought in from Southern Europe, to work in the mills, to make up for the labor shortage caused by migration to the West??

By virtue of his self-reliance, his individualism and his freedom from external restraint, the private eye is a perfect embodiment of the middle class conception of liberty, which amounts to doing what you please and let the devil take the hindmost.

At the same time, because the personal code of the detective coincides with the legal dictates of his society, because he likes to catch criminals, he is in middle class eyes a virtuous man.

Since a civilizational crisis involves also a crisis in private interests and in the ruling class, reaction is normally found among those who feel themselves to be among the ruling class.

The concept of labor as a special class is outmoded, and in the task confronting America as bastion of the free world, labor must learn to put the national interest first if it is itself to survive.

The soldiers themselves cannot stage a successful rebellion, it is assumed: but will their discontent spread to the officer class??

Therefore, under our longstanding allocation rules, on some of these channels no station other than the dominant ( class 1 ) -- A ) station is permitted to operate at night, so that the 1, -- A station can render service, interference free, wherever it can be received.

Such additional daytime class 2, assignments are appropriate if optimum use is to be made of these frequencies, and the Commission has over the years made a large number of them.

Staley Hanover ( Knight Dream-Sweetmite Hanover ) is a little on the small side but a very compact colt and looks like one to stand training and many future battles with colts in his class.

Consultation with architects, clients, real estate men, fabric houses and furniture companies is essential to the proper development of class problems just as in actual work.

As is well known, detergent actives belong to the chemical class consisting of moderately high molecular weight and highly polar molecules which exhibit the property of forming micelles in solution.

This is particularly true of highly charged ions, especially those ions which fall into the class of polyelectrolytes.

The class of the congruence is Af, since an arbitrary plane meets **zg in K points.

The congruence of its secants is therefore of order Af and class Af.

A final class of exceptional lines is identifiable from the following considerations: Since no two generators of Af can intersect, it follows that their image curves can have no free intersections.

Therefore, the congruence of its secants, that is the image of a general plane field of lines, is of order Af and class Af.

Finally, the image of a general bundle of lines is a congruence whose order is the order of the congruence of invariant lines, namely Af and whose class is the order of the image congruence of a general plane field of lines, namely Af.

Another great danger is that the emerging middle class will feel itself increasingly alienated from the political leaders who still justify their dominance by reference to the struggle for independence or the early phase of nationalism.

In some European countries, these closed social classes were given titles, followed mores and codes of behavior according to their closed social class, even wore distinctive dress.

This principle defined the closed system, and this principle was not a function of one's skin color or religion or economic class.

In the best of times, the European social system enforced elements of endogamy, closed occupation, culture, social class, affiliation and power-all of which define any caste system.

Up to reversal of the orientation of a simple closed curve, if it lies within one of the two crosscaps that make up the Klein bottle, then it is in homology class ( 1, 0 ) or ( 1, 1 ); if it cuts the Klein bottle into two Möbius bands, then it is in homology class ( 2, 0 ); if it cuts the Klein bottle into an annulus, then it is in homology class ( 0, 1 ); and if bounds a disk, then it is in homology class ( 0, 0 ).

In other set theories, such as New Foundations or the theory of semisets, the concept of " proper class " still makes sense ( not all classes are sets ) but the criterion of sethood is not closed under subsets.

He picked up a masters degree from Yale for giving an oral dissertation to the Yale graduating class, and later that year opened a small, private school in western Connecticut that was an instant success, though he quickly closed it and left town — likely due to a failed romance.

They are the smallest class of partial functions that includes the initial functions and is closed under composition, primitive recursion, and the μ operator.

The smallest class of functions including the initial functions and closed under composition and primitive recursion ( i. e. without minimisation ) is the class of primitive recursive functions.

The university had recently reopened after being closed for about half a century, and many students of the newly educated class adopted the Shining Path's radical ideology.

A vast generalisation of this class of rings which still resembles many properties of Tychonoff spaces but is also applicable in real algebraic geometry, is the class of real closed rings.

Business class passengers as well as members of the Priority Pass, Airport Angel ( including Diners Club ) and Metropolis regular customer programme have access to Linda Lounge, located in the closed area of the passenger terminal next to gate 7.

This " naturally " distinction demonstrates that the class of sentential adverbs is a closed class ( there is resistance to adding new words to the class ), whereas the class of adverbs that modify verbs isn't.

* Birkhoff's HSP Theorem, which states that a class of algebras is a variety if and only if it is closed under homomorphic images, subalgebras, and arbitrary direct products.

In these rites the magician's relationship to the supernatural and his entry into a closed professional class is established, often through rituals that simulate death and rebirth into a new life.

Auxiliary verbs are function words rather than content words, and are thus expected to constitute a closed class ( limited set ) of words in a given language.