For instance, if one is trying to prove a lemma for one reason or another, take a few moments to ask yourself questions such as
- If the lemma were proven, how would it be used?
- What features of the lemma are most important for you?
- Would a weaker lemma suffice?
- Is there a simpler formulation of the lemma?
- Is it worth trying to omit a hypothesis of the lemma, if that hypothesis seems hard to obtain in practice?