In a general way, problems which are in P are regarded as being ‘tractable’ (i.e. ‘soluble in an acceptable length of time’), for reasonably large n, on a fast modern computer, while problems in NP which are not in P are regarded as being ‘intractable’ (i.e. though soluble in principle, they are ‘insoluble in practice’) for reasonably large n – no matter what increases in operational computer speed, of any foreseeable kind, are envisaged.
