partial function

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partial function

[′pär·shəl ′fəŋk·shən]
(computer science)
A partial function from a set A to a set B is a correspondence between some subset of A and B which associates with each element of the subset of A a unique element of B.

partial function

A function which is not defined for all arguments of its input type. E.g.

f(x) = 1/x if x /= 0.

The opposite of a total function. In denotational semantics, a partial function

f : D -> C

may be represented as a total function

ft : D' -> lift(C)

where D' is a superset of D and

ft x = f x if x in D ft x = bottom otherwise

where lift(C) = C U bottom. Bottom (LaTeX \perp) denotes "undefined".
References in periodicals archive ?
Partial array A of size (m, n) over [SIGMA], a finite alphabet, is partial function A : [Z.
The patient has regained partial function of knee extensors and remains classified as ASIA Impairment Scale C (AIS C) with a motor incomplete spinal cord injury.
Pulmonologists know they can never restore normal lung function for their patients with chronic obstructive pulmonary disease; they can only help them hang on with partial function.
University of Illinois scientists have also discovered why it happens: soy restores partial function of that organ's key signalling pathway.
After the concepts and theories are introduced, the equivalence of computable partial function and recursive partial function are demonstrated, in part through proofs of the unsolvability of the halting problem and of the enumeration theorem.
In addition to these ten individuals, two other patients recovered partial function.
W is a partial function from set IxTm where W[i,t] is a quintuple <U[i], [[sigma][i,t].
1), where mi is the number of partial solutions, for partial function i.
Although the procedure has a high success rate--88% of the grafts retain at least partial function beyond 5 years--it is not practical in Japan, where the concept of cadaveric organ transplantation is only now gaining public support.
By a partial function we mean a relation that fails to be a function because it is not aplicable for certain arguments in the domain.
Until now, smaller libraries have had to settle for incomplete PC-based systems with partial function," Young said.
Then, every machine defines a partial function on natural numbers.

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