A
A C*-algebra A in which the closed unit ball of A+ isn't the closed convex
hull of the projections of A. (Note that the closed unit ball of positive elements of each hereditary C*-algebra A of a von Neumann algebra is the closed convex
hull of its projections ).
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The only projections of C([0,1]) are 0 and 1. So the closed convex
hull of C([0,1]) is {f |$c Î [0,1];f = c}, not equal to (C([0,1]))+1.
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On 22 Feb 2001, 00:19.