> a quantum computer that can do something that a classic computer can’t do at all, not just better at it. When speed is an aspect of the requirement, then it'

> a quantum computer that can do something that a classic computer can’t do at all, not just better at it. When speed is an aspect of the requirement, then it's something the other computer can't do. E.g. 'complete this calculation in n days on hardware x' or 'completed this calculation with time complexity t and memory complexity m'