 Note, however, that once the physical Church-Turing thesis is violated, arguably some computational notions cease to be autonomous. In other words, given that quantum computers may be able to efficiently solve classically intractable problems, hence re-describe the abstract space of computational complexity (Bernstein and Vazirani 1997), computational concepts and even computational kinds such as ‘an efficient algorithm’ or ‘the class NP’, become machine-dependent, and recourse to ‘hardware’ becomes inevitable in any analysis thereof (Hagar 2007).