[ivancho]

What is your certainty that that statement is true? What if it was a calculation which takes decades on a supercomputer?

[jusuhi]

At current rates, whatever is done on a supercomputer today is done by a cheap pocket-size device just decades later. So, I'm not too worried about this case.

One of the first famous examples of this is the four-coloring theorem. I don't know any serious mathematician who is not certain of that result.