Dear Fred,
Thanks for taking the time and effort to provide your feedback. I looked at your example.
I gave my example in simple terms in the hopes that the full extent of the idea would be understood. In my explanation of the problem, I should have made it clear that the key can be any character scalar or vector except ''. So, the key can have spaces or any other ⎕AV character. In fact, the key ken even be just a space.
The value can be any character or numeric scalar, array, or nested array containing anything including ''.
Given the above, neither ⊃ and ⊂, nor your code can handle those parameters. Box / unbox can.
Thanks.
Blake