Formally, a binary operation on a set S is called associative if it satisfies the associative law:

Formally, a topological space X is called compact if each of its open covers has a finite subcover.

Formally speaking, a collation method typically defines a total order on a set of possible identifiers, called sort keys, which consequently produces a total preorder on the set of items of information ( items with the same identifier are not placed in any defined order ).

Formally, a set S is called finite if there exists a bijection

Formally, these reside in a complex separable Hilbert space-variously called the " state space " or the " associated Hilbert space " of the system-that is well defined up to a complex number of norm 1 ( the phase factor ).

Formally, if is an open subset of the complex plane, a point of, and is a holomorphic function, then is called a removable singularity for if there exists a holomorphic function which coincides with on.

Formally, we have for the approximation to the full solution A, a series in the small parameter ( here called ), like the following:

Formally, they are partial derivatives of the option price with respect to the independent variables ( technically, one Greek, gamma, is a partial derivative of another Greek, called delta ).

Formally, however, a face is any of the lower dimensional boundaries of the polytope, more specifically called an n-face.

Formally, a hypergraph is a pair where is a set of elements called nodes or vertices, and is a set of non-empty subsets of called hyperedges or edges.

Formally, a Lie superalgebra is a ( nonassociative ) Z < sub > 2 </ sub >- graded algebra, or superalgebra, over a commutative ring ( typically R or C ) whose product, called the Lie superbracket or supercommutator, satisfies the two conditions ( analogs of the usual Lie algebra axioms, with grading ):

Formally, a Hopf algebra is a ( associative and coassociative ) bialgebra H over a field K together with a K-linear map S: H → H ( called the antipode ) such that the following diagram commutes:

Formally, an ultrametric space is a set of points with an associated distance function ( also called a metric )

Formally, the group was called Studiengesellschaft für Geistesurgeschichte ‚ Deutsches Ahnenerbe e. V.

Formally the neutral is called the “ grounded conductor ”; as of the 2008 NEC, the terms “ neutral conductor ” and “ neutral point ” have been defined in the Code to record what had been common usage.

Formally, the game ( coalitional game ) consists of a finite set of players, called the grand coalition, and a characteristic function denotes the power set of .</ ref > from the set of all possible coalitions of players to a set of payments that satisfies.

Formally called the Final Declaration of the Stresa Conference, its aim was to reaffirm the Locarno Treaties and to declare that the independence of Austria " would continue to inspire their common policy ".

Formally, a non-empty partially ordered set ( D, ≤) is called a Scott domain if the following hold:

Formally called " the Wigwam ", this immense edifice was located on Girard Avenue between 19th and 20th Streets, across from Philadelphia's Girard College.

Formally, the Ministry of Aeronautics was founded on January 20, 1941 and so its military branch called " National Air Forces ", changed to " Brazilian Air Force " ( Força Aérea Brasileira-FAB ) on May, 22.

Formally called Mills and Boon Classics and Mills and Boon Favourites.

Formally called The Best Of and Collection.

Formally called Modern Romance Extra.

In Latvia, Palm Sunday is called " Pussy Willow Sunday ", and pussy willows – symbolizing new life – are blessed and distributed to the faithful.

Willow plays an integral role within the inner circle of friends — called the Scooby Gang — who support Buffy Summers, a teenager gifted with superhuman powers to defeat vampires, demons, and other evil in the fictional town of Sunnydale.

In the beginning of the series, Hannigan used her own experiences in high school — which she called " overwhelmingly depressing "— to guide her portrayal of Willow.

Willow goes for months without any magic, helping Buffy track three geeks called The Trio who grandiosely aspire to be supervillains.

This subspecies has been called the Willow Goldfinch.

* Wikaskokiseyin ( Wee-kas-kookee-sey-yin, better known as Chief Sweet Grass, Chief of the Plains Cree, his mother was a captured Absaroke, as he grew up he was also called Apistchi-okimas-' Little Chief ', signed the Treaty 6 on 9 September 1876 at Fort Pitt, along with bands of Woodland Cree, Chipewyan, some Saulteaux, only a quarter of the participating groups were Plains Cree, while his successor as chief Wah-wee-oo-kah-tah-mah-hote (' Strike him on the back ') signed the Treaty 6 at Fort Carlton on the 28th August 1876 together with the Willow Cree, died 11 January 1877 in a shootout accident on the Plains, probably at Saint-Paul-des-Cris, Alberta )

The Rio Pueblo de Taos, also called Rio Pueblo and Red Willow Creek, is a small stream which flows through the middle of the pueblo compound.

Nearing Bridgwater on the M5 motorway it is possible to see the Willow Man sculpture, a striding human figure constructed from willow, sometimes called the Angel of the South ( see also Angel of the North ).

Most species stay within their breeding range all year, but make short seasonal movements ; many individuals of the Ptarmigan ( called Rock Ptarmigan in America ) and Willow Grouse ( called Willow Ptarmigan in America ) migrate hundreds of kilometers.

:* Hans Christian Andersen wrote a story called " Under the Willow Tree " ( 1853 ) in which children ask questions of a tree they call " willow-father ", paired with another entity called " elder-mother ".

:* " Green Willow " is a Japanese ghost story in which a young samurai falls in love with a woman called Green Willow who has a close spiritual connection with a willow tree.

:* In J. K. Rowling's Harry Potter and the Chamber of Secrets, and Harry Potter and the Prisoner of Azkaban, an old tree on the school grounds of Hogwarts is called the " Whomping Willow ".

It was called the Willow Run Expressway.

The child washes up on shore near a village inhabited by a race of dwarf-like people called Nelwyns ( derisively called " pecks " by humans ) and is found by the children of Willow Ufgood ( Warwick Davis ), a farmer and amateur conjurer.

The script called for Willow to restore Fin Raziel ( Patricia Hayes ) from a goat to her original human form.

Before the English name was standardised to Willow Warbler by William Yarrell in 1843, it was sometimes called " willow wren ".

* Humphrey Bogart-Bogart's parents owned a cottage ( called Willow Brook ) on Canandaigua Lake ( Seneca Point area ), where the family spent several summers when Humphrey was a boy.

Hudson was at first called Willow River and later named Buena Vista by Judge Joel Foster, founder of River Falls, after returning from the Mexican War where he fought in the Battle of Buena Vista.