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A multivalued dependency X Y signifies that if we choose any x actually occurring in the table ( call this choice x < sub > c </ sub >), and compile a list of all the x < sub > c </ sub > yz combinations that occur in the table, we will find that x < sub > c </ sub > is associated with the same y entries regardless of z.
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multivalued and dependency
Whereas the second, third, and Boyce – Codd normal forms are concerned with functional dependencies, 4NF is concerned with a more general type of dependency known as a multivalued dependency.
A Table is in 4NF if and only if, for every one of its non-trivial multivalued dependencies X Y, X is a superkey — that is, X is either a candidate key or a superset thereof .< ref name =" Fagin ">" A relation schema R * is in fourth normal form ( 4NF ) if, whenever a nontrivial multivalued dependency X Y holds for R *, then so does the functional dependency X → A for every column name A of R *.
A trivial multivalued dependency X Y is one where either Y is a subset of X, or X and Y together form the whole set of attributes of the relation.
A functional dependency is a special case of multivalued dependency.
multivalued and any
It can be formulated for functions of several variables, it can be extended to provide a ready formula for F ( g ( z )) for any analytic function F, and it can be generalized to the case f '( a ) = 0, where the inverse g is a multivalued function.
multivalued and table
In these equations, g < sub > 0 </ sub >, M and R < sup >*</ sup > are each single-valued constants, while P, L, T, and h are multivalued constants in accordance with the table below.
multivalued and <
* In general, α < sup > β </ sup > = exp ( β log α ) is multivalued, where " log " stands for the complex logarithm.
multivalued and all
The term " Pick system " has also come to be used as the general name of all operating environments which employ this multivalued database and have some implementation of Pick / BASIC and ENGLISH / Access queries.
multivalued and is
Since the function ƒ is not injective, the relation W is multivalued ( except at 0 ).
In mathematics, a multivalued function ( shortly: multifunction, other names: many-valued function, set-valued function, set-valued map, multi-valued map, multimap, correspondence, carrier ) is a left-total relation ; that is, every input is associated with at least one output.
The term " multivalued function " is, therefore, a misnomer because functions are single-valued.
The square root is multivalued.
Now, arg z is intrinsically multivalued.
The Pick operating system ( often called just " the Pick system " or simply " Pick ") is a demand-paged, multiuser, virtual memory, time-sharing computer operating system based around a unique " multivalued " database.
multivalued and with
In 1998 he published ( with Pavel V. Semenov ) the first monograph entirely dedicated to the theory of continuous selections of multivalued mappings ( Kluwer ).
Branch cuts allow one to work with a collection of single-valued functions, " glued " together along the branch cut instead of a multivalued function.
A correspondence with this additional property is thought of as the generalization of a function, rather than as a special case of a relation, and is referred to in other contexts as a multivalued function.
* Hyperstructure, an algebraic structure equipped with at least one multivalued operation
multivalued and same
When treated as multivalued functions, both sides produce the same set of values, being
multivalued and entries
** dupent: return multivalued results as separate entries
multivalued and .
The multivalued function corresponds to this inverse relation.
extended this to arbitrary multivalued analytic functions and gave informal aguments in its favor.
Schwarz integrability criterion, which makes them multivalued.
ENGLISH did not fully allow manipulating the 3-dimensional multivalued structure of data records.
All these theories are connected by a new type of multivalued gauge transformations.
However, since most central forces do not produce closed orbits ( see Bertrand's theorem ), the analogous vector rarely has a simple definition and is generally a multivalued function of the angle θ between r and.
The value of an abelian integral depends not only on the integration limits but also on the path along which the integral is taken, and it is thus a multivalued function of.
dependency and X
To emphasize this dependency, if f: X → Y is a measurable function, we will write
A non-prime attribute of R is an attribute that does not belong to any candidate key of R. A transitive dependency is a functional dependency in which X → Z ( X determines Z ) indirectly, by virtue of X → Y and Y → Z ( where it is not the case that Y → X ).
* X contains A ( that is, X → A is trivial functional dependency ), or
dependency and Y
In a functional dependency X → Y, every x determines exactly one y, never more than one.
A functional dependency FD: X → Y is called trivial if Y is a subset of X.
dependency and if
* A reflexive and symmetric relation is a dependency relation, if finite, and a tolerance relation if infinite.
A 2009 report in Gastroenterology suggests that PPIs may cause dependency by increasing gastric symptoms if they are discontinued.
: A functional dependency holds in a relation if:
: A functional dependency holds in a relation universe if it holds in all relations in.
: A functional dependency is trivial under a header if it holds in all relation universes over.
: The completion of an attribute set can be used to compute if a certain dependency is in the closure of a set of FDs.
In the dependency tree on the right, each node that dominates one or more other nodes corresponds to a phrase ; there are therefore 5 ( or 6 if the whole sentence is included ) phrases in the dependency tree.
Recently, some scholars have questioned whether Carter's energy plan, if it had been fully enacted, would have prevented some of the current economic difficulties caused by American dependency on foreign oil.
In July 2011 Duncan Smith said that tighter immigration controls are vital if Britain is to avoid “ losing another generation to dependency and hopelessness ”.
* In most spreadsheet systems, the dependency graph that connects one cell to another if the first cell stores a formula that uses the value in the second cell must be a directed acyclic graph.
For example, if that functional dependency occurs as a result of the transitive functional dependencies VIN → VehicleModel and VehicleModel → EngineCapacity then that would not result in a normalized relation.
In such a case, if a source file gains a new dependency ( e. g., if the programmer adds a new # include directive in a C source file ), then a discrepancy is introduced between the real dependencies and those that are used by the compilation system.
In practice, most source code has some dependency on the platform for which it is designed — even if a programmer uses a platform-independent programming language like Java, it is hard to write a large, useful program that is totally independent of its environment.
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