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In mathematics , a topos (plural "topoi" or "toposes") is a type of category that behaves like the category of sheaves of sets on a topological space (or more generally: on a site ).
Noncommutative geometry (NCG) is a branch of mathematics concerned with a geometric approach to noncommutative algebras , and with the construction of spaces which are locally presented by noncommutative algebras of functions (possibly in some generalized sense).
In mathematics, Zermelo–Fraenkel set theory with the axiom of choice , named after mathematicians Ernst Zermelo and Abraham Fraenkel and commonly abbreviated ZFC , is one of several axiomatic systems that were proposed in the early twentieth century to formulate a theory of sets without the paradoxes of naive set theory such as Russell's paradox .
In the foundations of mathematics , Russell's paradox (also known as Russell's antinomy ), discovered by Bertrand Russell in 1901, showed that the naive set theory created by Georg Cantor leads to a contradiction.
Naive set theory is one of several theories of sets used in the discussion of the foundations of mathematics . [ 1 ] Unlike axiomatic set theories, which are defined using a formal logic, naive set theory is defined informally, in natural language. It describes the aspects of mathematical sets familiar in discrete mathematics (for example Venn diagrams and symbolic reasoning about their Boolean algebra ), and suffices for the everyday usage of set theory concepts in contemporary mathematics.
In mathematics , twistor space is the complex vector space of solutions of the twistor equation .
Sir Roger Penrose FRS (born 8 August 1931), is an English mathematical physicist , recreational mathematician and philosopher .
Author's Note: 'Epic Pooh' was originally published as an essay by the BSFA , revised for its inclusion in the 1989 book Wizardry and Wild Romance, A Study of Epic Fantasy , and slightly revised again for this publication.
Author Kenneth Anderson with his dog Nipper
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by Dennis Crouch Mayo Collaborative Services v. Prometheus Labs., Inc.
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2012 March 12
T he Bible tells us that God created Adam and Eve just a few thousand years ago, by some fundamentalist interpretations. Science informs us that this is mere fiction and that man is a few million years old, and that civilization just tens of thousands of years old.
Richard Neustadt, who died in 2003, was the most influential scholar of the American Presidency.