Abstract
We discuss the A-function in the general setting of JB*-triples. Several results connecting the A-function with the distance of a vector to the Brown-Pedersen's quasi-invertible elements and extreme convex decompositions have been obtained for JB*-triples; these include JB*-triple analogues of some related C*-algebra results due to M. Rordam, L. Brown and G. Pedersen. (c) 2014 The Authors. Published by Elsevier Inc.