...would evaluating a(n uncollapsed) superposition in a Boolean context generate a warning/error or would it cause both branches of the code to be (tentatively) run and the results to be indeterminate until something is done to collapse the (expanding) superposition? ;)

Err...neither.

In a boolean context, a disjunctive superposition evaluates to true if any of its eigenstates is true, whilst a conjunctive superposition evaluates to true only if all of its eigenstates are true.

This could add "logic programming" to Perl's bag of paradigms.

Sssssssssshhhhhhhhhhhh!!!!!!! How the heck am I supposed to sneak these new paradigms in if you keep warning everybody beforehand??? ;-)

But, yes, that's the general idea. It would be rather nice to be able to code an n-ary max subroutine declaratively, like so:

    sub max (*@values) { any @values >= all @values }
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Especially since that version is vastly more amenable to internal parallelization.