Lots disheartened about novel maths theorems (6)

I believe the answer is:

lemmas

I'm a little stuck... Click here to teach me more about this clue!

'maths theorems' is the definition.
The definition and answer can be both related to communication as well as being plural nouns.
Maybe you can see a link between them that I don't see?

'lots disheartened about novel' is the wordplay.
'disheartened' says to hollow out the word (remove centre letters) (the middle or heart is removed).
'about' is an insertion indicator.
'novel' becomes 'emma' (novel by Jane Austen).
'lots' with its centre taken out is 'ls'.
'ls' enclosing 'emma' is 'LEMMAS'.

Can you help me to learn more?

(Another definition for lemmas that I've seen is " arguments".)

I've seen this clue in The Guardian.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.