Lemma and Prerequisite

Lemma noun - A subsidiary proposition that is assumed to be true in order to prove another proposition.

Prerequisite and lemma are semantically related. In some cases you can use "Prerequisite" instead a noun "Lemma".

Prerequisite noun - Something that is required in advance.

Lemma and prerequisite are semantically related. Sometimes you can use "Lemma" instead a noun "Prerequisite".