primitive recursive function
71Consistency — For other uses, see Consistency (disambiguation). In logic, a consistent theory is one that does not contain a contradiction.[1] The lack of contradiction can be defined in either semantic or syntactic terms. The semantic definition states that a …
72Metatheorem — In logic, a metatheorem is a statement about a formal system proven in a metalanguage. Unlike theorems proved within a given formal system, a metatheorem is proved within a metatheory, and may reference concepts that are present in the metatheory …
73Logical positivism — (also known as logical empiricism, scientific philosophy, and neo positivism) is a philosophy that combines empiricism the idea that observational evidence is indispensable for knowledge with a version of rationalism incorporating mathematical… …
74Set (mathematics) — This article gives an introduction to what mathematicians call intuitive or naive set theory; for a more detailed account see Naive set theory. For a rigorous modern axiomatic treatment of sets, see Set theory. The intersection of two sets is… …
75Logic — For other uses, see Logic (disambiguation). Philosophy …
76Countable set — Countable redirects here. For the linguistic concept, see Count noun. Not to be confused with (recursively) enumerable sets. In mathematics, a countable set is a set with the same cardinality (number of elements) as some subset of the set of… …
77Structure (mathematical logic) — In universal algebra and in model theory, a structure consists of a set along with a collection of finitary operations and relations which are defined on it. Universal algebra studies structures that generalize the algebraic structures such as… …
78Interpretation (logic) — An interpretation is an assignment of meaning to the symbols of a formal language. Many formal languages used in mathematics, logic, and theoretical computer science are defined in solely syntactic terms, and as such do not have any meaning until …
79Ambiguity — 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… …
80Model theory — This article is about the mathematical discipline. For the informal notion in other parts of mathematics and science, see Mathematical model. In mathematics, model theory is the study of (classes of) mathematical structures (e.g. groups, fields,… …
