Question:
What is a lemma?
Solution:
A proven statement used as a stepping-stone toward the proof of another statement is called lemma.
For example:
Euclid’s Division Lemma: Let a and b be any two positive integers.
Then, there exist unique integers q and r such that
$a=b q+r, 0 \leq r
If $b \mid a$ then $r=0$.
Otherwise, $r$ satisfies the stronger inequality $0