# completeness

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**Logical connective**— This article is about connectives in classical logic. For connectors in natural languages, see discourse connective. For connectives and operators in other logics, see logical constant. For other logical symbols, see table of logic symbols. In… …82

**Ultrafilter**— In the mathematical field of set theory, an ultrafilter on a set X is a collection of subsets of X that is a filter, that cannot be enlarged (as a filter). An ultrafilter may be considered as a finitely additive measure. Then every subset of X is …83

**Hilbert's program**— Hilbert s program, formulated by German mathematician David Hilbert in the 1920s, was to formalize all existing theories to a finite, complete set of axioms, and provide a proof that these axioms were consistent.Hilbert proposed that the… …84

**Infinitary logic**— Those unfamiliar with mathematical logic or the concept of ordinals are advised to consult those articles first. An infinitary logic is a logic that allows infinitely long statements and/or infinitely long proofs. Some infinitary logics may have… …85

**Cook–Levin theorem**— In computational complexity theory, the Cook–Levin theorem, also known as Cook s theorem, states that the Boolean satisfiability problem is NP complete. That is, any problem in NP can be reduced in polynomial time by a deterministic Turing… …86

**War artist**— For information about the genre, see War art. A war artist depicts some aspect of war through art; this might be a pictorial record or it might commemorate how war shapes lives. [1] War artists have explored a visual and sensory dimension of war… …87

**You Ain't Gonna Need It**— In software engineering, YAGNI, short for You Ain t Gonna Need It , suggests to programmers that they should not add functionality until it is necessary. Ron Jeffries writes, Always implement things when you actually need them, never when you… …88

**IP (complexity)**— In computational complexity theory, the class IP is the class of problems solvable by an interactive proof system. The concept of an interactive proof system was first introduced by Goldwasser, et al. in 1985. An interactive proof system consists …89

**Boolean algebra (logic)**— For other uses, see Boolean algebra (disambiguation). Boolean algebra (or Boolean logic) is a logical calculus of truth values, developed by George Boole in the 1840s. It resembles the algebra of real numbers, but with the numeric operations of… …90

**Quality of models**— Modeling is an integral part of many technical fields, including engineering, economics, and software engineering. In this context, a model is a formal representation of an organizational system, such as a business model or a formal description… …