projective system
121Liste des articles de mathematiques — Projet:Mathématiques/Liste des articles de mathématiques Cette page recense les articles relatifs aux mathématiques, qui sont liés aux portails de mathématiques, géométrie ou probabilités et statistiques via l un des trois bandeaux suivants  …
122duality — /dooh al i tee, dyooh /, n. 1. a dual state or quality. 2. Math. a symmetry within a mathematical system such that a theorem remains valid if certain objects, relations, or operations are interchanged, as the interchange of points and lines in a… …
123List of important publications in mathematics — One of the oldest surviving fragments of Euclid s Elements, found at Oxyrhynchus and dated to circa AD 100. The diagram accompanies Book II, Proposition 5.[1] This is a list of important publications in mathematics, organized by field. Some… …
124Quantum nondemolition measurement — Quantum nondemolition (QND) measurement is a measurement of a quantum system, which preserves the integrity of the system and the value of the measured observable. This allows exactly the same system to be measured repeatedly. The term… …
125Intentionality — The term intentionality is often simplistically summarised as aboutness . According to the Oxford English Dictionary, it is the distinguishing property of mental phenomena of being necessarily directed upon an object, whether real or imaginary .… …
126Orthogonal group — Group theory Group theory …
127Orbifold — This terminology should not be blamed on me. It was obtained by a democratic process in my course of 1976 77. An orbifold is something with many folds; unfortunately, the word “manifold” already has a different definition. I tried “foldamani”,… …
128List of differential geometry topics — This is a list of differential geometry topics. See also glossary of differential and metric geometry and list of Lie group topics. Contents 1 Differential geometry of curves and surfaces 1.1 Differential geometry of curves 1.2 Differential… …
