User blog comment:Alemagno12/Quick poll/@comment-27513631-20180824204752

Sketch an injection/surjection from the family of functions into \(\alpha\) for an upper/lower bound. You can't actually be sure you're correct if you do less, and if you do more then it's often a case of diminishing returns. It's sometimes possible to produce an injection at a glance, but it may be more involved, and surjections are usually rather involved.