Category of modulesIn algebra, given a ring R, the category of left modules over R is the whose are all left modules over R and whose morphisms are all module homomorphisms between left R-modules. For example, when R is the ring of integers Z, it is the same thing as the . The category of right modules is defined in a similar way. One can also define the category of bimodules over a ring R but that category is equivalent to the category of left (or right) modules over the enveloping algebra of R (or over the opposite of that).
Garden toolA garden tool is any one of many tools made for gardening and landscaping, which overlap with the range of tools made for agriculture and horticulture. Garden tools can be divided into hand tools and power tools. Hand tool Today's garden tools originated with the earliest agricultural implements used by humans. Examples include the hatchet, axe, sickle, scythe, pitchfork, spade, shovel, trowel, hoe, fork, and rake. In some places, the machete is common. The earliest tools were made variously of wood, flint, metal, tin, and bone.
Supply chain sustainabilitySupply-chain sustainability is the impact a company’s supply chain can make in promoting human rights, fair labor practices, environmental progress and anti-corruption policies. There is a growing need for integrating sustainable choices into supply-chain management. An increasing concern for sustainability is transforming how companies approach business. Whether motivated by their customers, corporate values or business opportunity, traditional priorities such as quality, efficiency and cost regularly compete for attention with concerns such as working conditions and environmental impact.
City status in the United KingdomCity status in the United Kingdom is granted by the monarch of the United Kingdom to a select group of communities, which might or might not meet the generally accepted definition of cities. , there are 76 cities in the United Kingdom—55 in England, seven in Wales, eight in Scotland, and six in Northern Ireland. Although it carries no special rights, the status of city can be a marker of prestige and confer local pride. The status does not apply automatically on the basis of any particular criterion, though in England and Wales it was traditionally given to towns with diocesan cathedrals.
City limitsCity limits or city boundaries refer to the defined boundary or border of a city. The area within the city limit can be called the city proper. Town limit/boundary and village limit/boundary apply to towns and villages. Similarly, corporate limit is a legal name that refers to the boundary of municipal corporations. In some countries, the limit of a municipality may be expanded through annexation.
Proto-cityA proto-city is a large, dense Neolithic settlement that is largely distinguished from a city by its lack of planning and centralized rule. While the precise classification of many sites considered proto-cities is ambiguous and subject to considerable debate, common examples include Jericho, Çatalhöyük and the mega-sites of the Cucuteni-Trypillia culture. Sites of the Ubaid period in Mesopotamia have also been classed as proto-cities.
Relation (mathematics)In mathematics, a binary relation on a set may, or may not, hold between two given set members. For example, "is less than" is a relation on the set of natural numbers; it holds e.g. between 1 and 3 (denoted as 1
Apollo 15Apollo 15 (July 26 - August 7, 1971) was the ninth crewed mission in the United States' Apollo program and the fourth to land on the Moon. It was the first J mission, with a longer stay on the Moon and a greater focus on science than earlier landings. Apollo 15 saw the first use of the Lunar Roving Vehicle. The mission began on July 26 and ended on August 7, with the lunar surface exploration taking place between July 30 and August 2.
Equality (mathematics)In mathematics, equality is a relationship between two quantities or, more generally two mathematical expressions, asserting that the quantities have the same value, or that the expressions represent the same mathematical object. The equality between A and B is written A = B, and pronounced "A equals B". The symbol "=" is called an "equals sign". Two objects that are not equal are said to be distinct. For example: means that x and y denote the same object. The identity means that if x is any number, then the two expressions have the same value.
Apollo 17Apollo 17 (December 7–19, 1972) was the eleventh and final mission of NASA's Apollo program, the sixth and most recent time humans have set foot on the Moon or traveled beyond low Earth orbit. Commander Gene Cernan and Lunar Module Pilot Harrison Schmitt walked on the Moon, while Command Module Pilot Ronald Evans orbited above. Schmitt was the only professional geologist to land on the Moon; he was selected in place of Joe Engle, as NASA had been under pressure to send a scientist to the Moon.
