taskID = selectATask()
verifier = getVerifierForTask(taskId)
solution = shortestSolutionForTask(taskID)

if not verifier(solution) then error 'Sanity check failed' end
if verifier '' then error 'Sanity check failed (or problem is trivial)' end

while shouldRun() do
  solution2 = shorten(solution)
  if solution2 == nil then break end
  if verifier(solution2) then
    solution = solution2
    print('Shortened solution to '..#solution2..' chars')
  end
end