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New coins from old, smoothly. (English) Zbl 1238.41007
Given a coin with unknown probability of heads $$p$$, as well as a fair coin, the authors would like to simulate a coin with probability of heads $$f(p)$$, where $$f:[0,1]\to (0,1)$$ is a known function. First, the authors define the simulation rate for a simulation algorithm. Next, they recall some basic results regarding Bernstein polynomials, Bernstein basis, Bernstein coefficients, Bernstein-positive consistent approximation from below, Bernstein-positive consistent approximation from above. The relationship between Bernstein-positive approximation and smoothness is then established. Next, Lorentz operators and simultaneous approximation are examined. An iterative construction of Bernstein-positive consistent approximations schemes is very clean presented. Finally, the authors prove that G. G. Lorentz’s Claim 10 [Math. Ann. 151, 239–251 (1963; Zbl 0116.04602)] is invalid.

##### MSC:
 41A10 Approximation by polynomials 41A25 Rate of convergence, degree of approximation
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##### References:
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