It came from solving an impossible problem, something that no one thought would ever get solved.

I don't think we should count this an impossible problem.

I know you don't have any domestic ties so it shouldn't be an impossible problem.

But she was afraid to let herself acknowledge it, because then she'd have an impossible problem.

Indecisive, probably, to the point where she could see impossible problems in doing anything at all.

A brilliant solution to what had been an impossible problem.

It can also lead to creative solutions for even seemingly impossible problems.

One would need to be young now and to have been young then as well, to decide that impossible problem.

It became impossible to sweep the problem under the carpet.

I do not know whether the Council has considered this, but to me it appears to be a totally impossible juridical problem.