A bilinear version of Holsztyński's theorem on isometries of C(X)-spaces
A bilinear version of Holsztyński's theorem on isometries of C(X)-spaces
We prove that, for a compact metric space $X$ not reduced to a point, the existence of a bilinear mapping $\diamond :C(X)\times C(X)\to C(X)$ satisfying $\Vert f\diamond g\Vert =\Vert f\Vert\, \Vert g\Vert $ for all $f,g\in C(X)$ is equivalent to the unco