# Preserving

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**Dynamical system (definition)**— This article presents the many ways to define a dynamical system. See the main article, dynamical system, for an overview of the topic. The dynamical system concept is a mathematical formalization for any fixed rule which describes the time… …72

**Vinyl disc records preservation**— refers to the preventative measures taken to defend against damage and slow degradation, and to maintain fidelity of singles, 12 singles, EP, LP in 45 or 33 1/3 rpm disc recordings. LPs are most often in the 12” format, although very early vinyl… …73

**Oral history preservation**— is the field that deals with the care and upkeep of oral history materials, whatever format they may be in. Oral history is a method of historical documentation, using interviews with living survivors of the time being investigated. Oral history… …74

**Dismissal of U.S. attorneys controversy timeline**— Dismissal of U.S. attorneys controversy (v · d · e …75

**Dismissal of U.S. attorneys controversy hearings**— Dismissal of U.S. attorneys controversy (v · d · e …76

**Islamic arts**— Visual, literary, and performing arts of the populations that adopted Islam from the 7th century. Islamic visual arts are decorative, colourful, and, in religious art, nonrepresentational; the characteristic Islamic decoration is the arabesque.… …77

**biblical literature**— Introduction four bodies of written works: the Old Testament writings according to the Hebrew canon; intertestamental works, including the Old Testament Apocrypha; the New Testament writings; and the New Testament Apocrypha. The Old… …78

**Category theory**— In mathematics, category theory deals in an abstract way with mathematical structures and relationships between them: it abstracts from sets and functions to objects and morphisms . Categories now appear in most branches of mathematics and in… …79

**Differential geometry**— A triangle immersed in a saddle shape plane (a hyperbolic paraboloid), as well as two diverging ultraparallel lines. Differential geometry is a mathematical discipline that uses the techniques of differential and integral calculus, as well as… …80

**Dynamical system**— This article is about the general aspects of dynamical systems. For technical details, see Dynamical system (definition). For the study, see Dynamical systems theory. Dynamical redirects here. For other uses, see Dynamics (disambiguation). The… …