On Sat, Mar 28, 2009 at 10:39:01AM -0300, Daniel Ruoso wrote: > That happens because $pa and $pb are a singular value, and that's how > junctions work... The blackjack program is an example for sets, not > junctions. > > Now, what are junctions good for? They're good for situation where it's > collapsed nearby, which means, it is used in boolean context soon > enough. Or where you know it's not going to cause the confusion as in > the above code snippet.
Unfortunately, it is extremely common to follow up a boolean "is this true" with either "if so, how" and/or "if not, why not". A boolean test is almost always the first step toward dealing with the consequences, and that almost always requires knowing not only what the result of the boolean test were, but which factors caused it to have that result. The canonical example of quantum computing is using it to factor huge numbers to break an encryption system. There you divide the huge number by the superposition of all of the possible factors, and then take the eigenstate of the factors that divide evenly to eliminate all of the huge pile of potential factors that did not divide evenly. Without being able to take the eigenstate, the boolean answer "yes, any(1..n-1) divides n" is of very little value.
