[weinzierl]

Verifiable means you can find a proof that a solution is correct. I am stating that the effort to find this proof can never be more effort than constructing the solution in the first place.

I think where the line of argumentation in the article derails is that the author confused finding a solution with coming up with any odd candidate that could be a solution. The former is serious effort, the latter is trivial. Their Sudoku example is the former, their article example the latter