How to express the maximum value of an array variable in CVX for writing subsequent constraint conditions

It is known that S is a three-dimensional array variable, so how to define Supper in CVX?

If Supper is input data and has the same dimensions as Suvw,you can use

Perhaps there is some indexing involved? Your question is unclear. When you copy some complicated notation out of context, you can’t expect forum readers to understand what it means,

If you want the maximum of S, you can use max(max(max(S))) or max(S(:)) . But you can’t multiply that by S because that is neither convex nor concave.

Thank you very much!