Proof. [02VM]
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Proof.
Let be an approachable toric metric. By Corollary 5.17 the function is bounded. By approachability there is a sequence of smooth (resp. algebraic) semipositive metrics that converges to . Since is toric, . Hence, the sequence of toric metrics also converges to . We denote . By Proposition 5.38 and Proposition 5.67 the functions are concave. Since the sequence converge uniformly to , the latter is concave.
Let now be a concave function on such that is bounded. Then determines a metric on the restriction of to . Since , by Proposition 3.81 there is a sequence of rational piecewise affine concave functions that converge uniformly to and with . By Remark 5.46, the functions can be extended to continuous functions on . Therefore, can be extended to a continuous function on . Consequently the metric can be extended to . Let be the metric associated to . Then the sequence of metrics converges to . By Corollary 5.28, the metrics are approachable. We deduce that is approachable. ∎