  A typical oracle problem is finding which software program is installed on a
computer, by running the computer and testing its input-output behaviour. The
program is randomly chosen from a set of programs known to the problem solver.
As well known, some oracle problems are solved more efficiently by using
quantum algorithms; this naturally implies changing the computer to quantum,
while the choice of the software program remains sharp. In order to highlight
the non-mechanistic origin of this higher efficiency, also the uncertainty
about which program is installed must be represented in a quantum way.
