Chisini mean

In mathematics, a function f of n variables


 * x1, ..., xn

leads to a Chisini mean M if for every vector &lt;x1 ... xn&gt;, there exists a unique M such that


 * f(M,M, ..., M) = f(x1,x2, ..., xn).

The arithmetic, harmonic, geometric, generalised, Heronian and quadratic means are all Chisini means, as are the weighted variants thereof.