I would go further and suggest that it is proof positive of life after death.
It is proof positive that our financial arrangements for student support have not deterred an increasing number of people going into higher education.
If recruitment does not improve, then it is proof positive that the people have rejected this policy.
To have increased expenditure in real terms during the years that we have been in office is proof positive that we are proud of it.
It has not worked, but perhaps we should take that as proof positive of the vacuity of border controls in any case.
The fact that he could describe it as merely "quite complex" is proof positive that he has not even tried to read it.
The certificate of disrepair is proof positive that they have not been done.
That would be acceptable as proof positive that the candidate had acquired a certain educational qualification.