In challenges on this site, particularly code-golf, answers are sometimes given that you can neither read nor test. If the answer is, for example, the shortest, should you still accept it?
As an example, consider code-golf answers written in APL. It is likely that I won't be able to read any of it and there is no free APL compiler/interpreter as far as I know so I can't test it either. Should I just believe that it does whatever the answerer says it does and award the win?