Does anyone know if this will actually work?
@intersection = @alphas =~ @betas;
I seriously doubt it. Larry has never even hinted that
=~ will operate like that in a list context.
Of course, if superpositions do get in then this:
@intersection = eigenstates(any @alphas =~ any @betas);
And it's possible that the eigenstates operator is superfluous; that a superposition in a list context just yields its eigenstates automatically. In which case you only need this:
@intersection = any @alphas =~ any @betas;