constructive function
81Ambiguity — Sir John Tenniel s illustration of the Caterpillar for Lewis Carroll s Alice s Adventures in Wonderland is noted for its ambiguous central figure, whose head can be viewed as being a human male s face with a pointed nose and pointy chin or being… …
82Decision problem — A decision problem has only two possible outputs, yes or no (or alternately 1 or 0) on any input. In computability theory and computational complexity theory, a decision problem is a question in some formal system with a yes or no answer,… …
83Recursively enumerable set — In computability theory, traditionally called recursion theory, a set S of natural numbers is called recursively enumerable, computably enumerable, semidecidable, provable or Turing recognizable if: There is an algorithm such that the set of… …
84David Hilbert — Hilbert redirects here. For other uses, see Hilbert (disambiguation). David Hilbert David Hilbert (1912) Born …
85Natural deduction — In logic and proof theory, natural deduction is a kind of proof calculus in which logical reasoning is expressed by inference rules closely related to the natural way of reasoning. This contrasts with the axiomatic systems which instead use… …
86Denotational semantics — In computer science, denotational semantics (initially known as mathematical semantics or Scott–Strachey semantics) is an approach to formalizing the meanings of programming languages by constructing mathematical objects (called denotations)… …
87Ε₀ — In mathematics, the epsilon numbers are a collection of transfinite numbers whose defining property is that they are fixed points of an exponential map. Consequently, they are not reachable from 0 via a series of applications of the chosen… …
88Ordinal notation — In mathematical logic and set theory, an ordinal notation is a finite sequence of symbols from a finite alphabet which names an ordinal number according to some scheme which gives meaning to the language. There are many such schemes of ordinal… …
89Finitary relation — This article sets out the set theoretic notion of relation. For a more elementary point of view, see Binary relation. For a combinatorial viewpoint, see Theory of relations. For other uses, see Relation (disambiguation). In set theory and logic,… …
90Löwenheim–Skolem theorem — In mathematical logic, the Löwenheim–Skolem theorem, named for Leopold Löwenheim and Thoralf Skolem, states that if a countable first order theory has an infinite model, then for every infinite cardinal number κ it has a model of size κ. The… …
