noun
lemma
A proposition proved to help establish a larger theorem.
This lemma helps us prove the theorem about prime numbers.
Etymology
Greek lēmma meant something taken or an assumption. Mathematics uses it for a proposition established so that it can be taken into a larger proof.
More examples
- We first prove a lemma about continuous functions.
- Two earlier lemmas supply the key steps in this proof.
- The theorem follows directly from the lemma.
Forms
lemma · lemmas · lemmata
Similar words
- proposition
- Any stated mathematical claim, not necessarily a supporting result.
- theorem
- Usually a main mathematical result, rather than a supporting step.